Myron and Dorothy Sammons appeal a decision of the United States Tax Court partially disallowing their deduction of $548,380 for the donation of certain Indian artifacts to the Museum of Native American Cultures. The Tax Court determined that the value of the donation on the date of the gift was $140,000 and reduced the deduction accordingly. The reduced amount was equal to what the Sammons had paid for the artifacts less than a year before making their contribution to the museum. The Sammons also appeal the Tax Court’s approval of a negligence penalty imposed by the Commissioner of Internal Revenue. The Commissioner appeals the Tax Court’s determination that the Sam-mons could include, among the items for which their charitable deduction was taken, artifacts incorporating certain feathers and other parts of birds protected by the Bald Eagle Protection Act, 16 U.S.C. §§ 668-668d, the Migratory Bird Treaty Act, 16 U.S.C. §§ 703-711, and the Endangered Species Act, 16 U.S.C. §§ 1531-1543.
We have jurisdiction pursuant to 26 U.S.C. § 7482(a). We affirm the Tax Court’s partial disallowance of the deduction and the inclusion of the items incorporating the protected bird elements. We reverse the Tax Court’s approval of the negligence penalty.
I
FACTS AND PROCEEDINGS
The opinion of the Tax Court contains a full rendition of the facts of this case.
See Sammons v. Commissioner,
The Pacific Northwest Indian Center, Inc. was founded by Father Wilfred Schoenberg, a Jesuit priest, to foster the study of North American Indian history and culture. From 1966 to 1977, Father Schoenberg served as president and curator of the Museum of North American Cultures, a museum operated by the Indian Center in Spokane, Washington. To further the museum’s goals, Father Schoenberg sought investors who would donate artifacts based upon appraisals of fair market value that would exceed the cost of the donated items.
In January 1977, Father Schoenberg became aware that the Stuart Collection of artifacts might be available for contribution to the museum. The Stuart Collection contained artifacts from the Plains and Plateau Indians and included items such as painted buffalo hides, buckskin clothing, medicine pipes, war bonnets, human scalps, medicine rattles made from buffalo scro-tums and many other items. The most important artifact in the collection was a rare Blackfoot Indian “thunder pipe,” a medicine pipe of religious significance to the Blackfoot tribe. The thunder pipe comprised a number of items wrapped together in a single hide. The bundle contained a sacred medicine pipe, an ermine pelt, the bodies of two weasels, an effigy head of a crane, a bone dance whistle, deer bones, a feather bundle with hawk bells, other feathers, medicine wands used for gambling, braided sweet grass, a child’s buckskin moccasin with medicine stones inside, a flute made from a rifle barrel and other artifacts. 1 The thunder pipe constituted a significant part of the Stuart Collection’s value.
*333 Through two art dealers contacted by Father Schoenberg, Mr. and Mrs. Sammons learned of the collection’s availability. Their attorney and accountant advised them that they could donate the collection to the museum and claim a deduction for its appraised value, even though the appraised value exceeded its cost. The Sam-mons bought the Stuart Collection for $140,000. They did so expecting to receive an appraisal showing the value of the collection to be $500,000. When they later learned that the art dealers who had bought the collection for them had paid only $60,000 for it, they demanded that these dealers supplement the collection to raise its worth to $500,000. The art dealers then began to buy other collections of Indian art and memorabilia. By March 30, 1977, substantial additional items had been acquired, and by letter dated April 2, 1977, Father Schoenberg advised the Sammons that the entire collection was in the museum’s possession and had a fair market value in excess of $500,000. This collection, which included the Stuart Collection and the additional items bought by the art dealers for the Sammons, was inventoried and photographed in June 1977. This entire collection, which we refer to as the “Sam-mons Collection,” was then appraised at values of $540,185 and $548,380. In December 1977, the Sammons formally donated the Sammons Collection to the museum.
On their 1977 income tax return, the Sammons claimed a charitable contribution for the Sammons Collection in the sum of $548,380. Because of annual limitations, the 1977 deduction was limited to $192,108. The balance of the deduction was carried over into the Sammons’ 1978 and 1979 tax returns. On audit, the Commissioner disallowed these deductions and imposed a negligence penalty under section 6653(a) of the Tax Code. The Sammons filed a petition for redetermination of liability in the Táx Court. At the Tax Court hearing, the Sam-mons presented an appraisal jointly prepared by Dr. Frederick J. Dockstader and Mr. Alton R. Packard, in addition to the letter appraisal that had been furnished by the museum and the two appraisals they had relied upon in claiming their deduction. The Dockstader-Packard appraisal valued the collection at $422,410. The Commissioner presented an appraisal valuing the donated collection at between $66,000 and $100,000.
The Tax Court rejected all of the Sam-mons’ appraisals, as well as the appraisal submitted by the Commissioner. The Tax Court found that the Sammons’ $140,000 cost of the Sammons Collection was the best indicator of its fair market value at the time the collection was contributed to the museum. This amount included the artifacts that incorporated the protected bird elements, which we hereafter refer to as the “Eagle Artifacts.”
II
VALUE OF THE SAMMONS COLLECTION
The Treasury regulations implementing section 170 of the Tax Code provide that “[i]f a charitable contribution is made in property other than money, the amount of the contribution is the fair market value of the property at the time of contribution. ...” 26 C.F.R. § 1.170A-l(c)(l). The regulations define fair market value as “the price at which the property would change hands between a willing buyer and a willing seller, neither being under any compulsion to buy or sell and both having reasonable knowledge of relevant facts.”
Id.
§ 1.170A-l(c)(2). It is the rule in this circuit that the Tax Court’s determination of the value of property is a finding of fact, which we will reverse only for clear error.
Bryant v. Commissioner,
Complex factual inquiries such as valuation require the trial judge to evaluate a number of facts: whether an expert appraiser’s experience and testimony entitle his opinion to more or less weight; whether an alleged comparable sale fairly approximates the subject property’s market value; and the overall cogency of each expert’s analysis. Trial courts have *334 particularly broad discretion with respect to questions of valuation.
Ebben v. Commissioner,
Mr. and Mrs. Sammons argue that although valuation is a question of fact reviewed for clear error, the method of valuation used by the trial court is a question of law reviewed de novo. They cite
Zanuck v. Commissioner,
While it is true “that the subject of yardsticks for the evaluation of [property] ... presents] a question of law reviewable by this court,”
Zanuck,
The Tax Court did not abuse its discretion in rejecting the appraisals. As we observed in
Ebben v. Commissioner,
the trial court has broad discretion to evaluate “the overall cogency of each expert’s analysis.”
The Sammons argue further, that even if the Tax Court correctly rejected their experts’ appraisals, the court erred in limiting their deduction to the $140,000 cost of the donated artifacts. We disagree.
Valuation is a question of fact. Based on the record as a whole, the Tax Court found that cost was the best indicator of the fair market value of the collection at the time it was contributed to the museum. The Sammons’ own witnesses testified that the value of the Sammons Collection did not increase in value simply because the individual elements were brought together in one collection.
Ill
THE EAGLE ARTIFACTS
The Commissioner contends the Sammons should be disallowed a deduction *335 for the Eagle Artifacts. These artifacts consisted of thirty-five items that incorporated feathers, claws, or other parts of birds protected under the Bald Eagle Protection Act, 16 U.S.C. §§ 668-668d, the Migratory Bird Treaty Act, 16 U.S.C. §§ 703-711, and the Endangered Species Act, 16 U.S.C. §§ 1531-1543. First, the Commissioner argues that relevant federal statutes prohibited the Sammons from obtaining title to the Eagle Artifacts. Second, even if the Sammons had title to the Eagle Artifacts, the Commissioner contends that allowing a deduction for contribution of these items to the museum will frustrate public policy. The Tax Court rejected both of these arguments. So do we.
A. Title to the Eagle Artifacts
The Eagle Protection Act makes it a federal crime to
take, possess, sell, purchase, barter, offer to sell, purchase or barter, transport, export or import, at any time or in any manner, any bald eagle commonly known as the American eagle, or any golden eagle, alive or dead, or any part, nest, or egg thereof____
16 U.S.C. § 668(a). Similarly, the Migratory Bird Treaty Act provides that
it shall be unlawful at any time, by any means or in any manner, to pursue, hunt, take, capture, kill, attempt to take, capture, or kill, possess, offer for sale, sell, offer to barter, barter, offer to purchase, purchase, deliver for shipment, ship, export, import, cause to be shipped, exported, or imported, delivered for transportation, transport or cause to be transported, carry or cause to be carried, or receive for shipment, transportation, carriage, or export, any migratory bird, any part, nest, or egg of any such bird, or any product, whether or not manufactured, which consists, or is composed in whole or in part, of any such bird or any part, nest, or egg thereof____
16 U.S.C. § 703.
It appears the Sammons may have violated federal law when they purchased the Eagle Artifacts. But it does not follow that the Sammons did not have title to the Eagle Artifacts when they made their contribution. From the statutes we discern only that a violation can result in criminal or civil sanctions, including forfeiture of protected items.
See
16 U.S.C. § 668(a)-(b) (Eagle Protection Act); 16 U.S.C. § 707 (Migratory Bird Treaty Act);
Sammons v. Commissioner,
The Commissioner argues “that where a statute expressly forbids or penalizes a person from entering into a certain kind of contract, the contract itself is void.” (citing S. Williston, A Treatise on the Law of Contracts § 1763 (3d ed. 1972)). The Commissioner’s reliance on Williston is misplaced. Professor Williston does not suggest that a third party may have a court declare an illegal contract void. Rather, if a statute prohibits an agreement or sale, the result is “that the courts will not lend their aid to any attempted enforcement of the agreement by the parties.” Id. § 1763, at 203. This rule is echoed by other commentators. See, e.g., Restatement (Second) of Contracts ch. 8, Topic 1 introductory note (“This Restatement is concerned with whether a promise is enforceable and not with whether some other sanction has been attached to the act of making or performing it in such a way as to make that act ‘illegal.’ ”); J. Calamari & J. Perillo, The Law of Contracts § 22-5, at 785 (2d ed. 1977) (“Where performance has been entered upon under an illegal bargain the general rule is that the court will leave the parties where it finds them.”).
The Commissioner also relies on
In re Pajarito American Indian Art, Inc.,
B. Public Policy
The Commissioner next contends the Sammons should be denied any deduction for their contribution of the Eagle Artifacts on the ground of public policy. The Commissioner argues that federal law makes it illegal to acquire or possess the Eagle Artifacts. To allow the Sammons a deduction for donating the artifacts to the museum would encourage a violation of federal law by subsidizing, through tax benefits flowing from the donation, an illegal transaction. We find this argument unpersuasive in the context of this case.
Income tax deductions “are a matter of grace and Congress can ... disallow them as it chooses.”
Commissioner v. Sullivan,
The Supreme Court has emphasized the high priority Congress has assigned to the policy of protecting endangered wildlife species such as the Eagle Artifacts involved in this case.
See, e.g., United States v. Dion,
IV
THE NEGLIGENCE PENALTY
The Sammons also challenge the Tax Court’s affirmance of the Commissioner’s imposition of a negligence penalty un
*337
der 26 U.S.C. § 6653(a). Section 6653(a) permits the Commissioner to impose an addition to tax for an underpayment “due to negligence or intentional disregard of rules and regulations (but without intent to defraud).”
Hansen v. Commissioner,
Negligence within the meaning of section 6653(a) is measured by the “reasonable, prudent person standard.”
Id.
(citing
Zmuda v. Commissioner,
Although the Tax Court rejected the appraisals submitted by Mr. and Mrs. Sam-mons, it found that Dr. Dockstader and Mr. Packard, who jointly valued the collection at $422,440, were exceptionally well qualified appraisers.
See Sammons v. Commissioner,
This conclusion accords with cases decided by the Tax Court. In
Biagiotti v. Commissioner,
the Tax Court found that although the taxpayers’ expert appraiser’s report was not entitled to any probative weight in determining the fair market value of a collection of Pre-Columbian artifacts, imposing a negligence penalty was inappropriate because the taxpayers had no reason to question their expert’s ability or reliability.
3
Biagiotti v. Commissioner,
V
CONCLUSION
We affirm the Tax Court’s limitation of the Sammons’ deduction to the cost of the *338 donated artifacts, including the Eagle Artifacts. We reverse the imposition of the negligence penalty against the Sammons. The parties shall bear their own costs for this appeal.
AFFIRMED IN PART AND REVERSED IN PART.
Notes
. The legend of the thunder pipe is unusual. It is well told in the Tax Court’s opinion.
See Sammons v. Commissioner,
. The Sammons also argue that they relied on the advice of “their attorneys, accountant and a Jesuit priest” in preparing their tax returns. The more important question, however, is whether the Sammons acted in a reasonable and prudent manner in claiming that the fair market value of the Sammons Collection was $548,380 at the time it was contributed to the museum.
. In
Biagiotti,
the taxpayers relied on a valuation report prepared by an appraiser whose reputation for credibility and reliability was less than pristine.
See
