Ariz. Rev. Stat. § 45-2261
B. All purchases and contracts made by the authority for material or services other than personal or professional services shall be made after advertising in a manner and time sufficiently in advance of opening bids as the authority deems adequate to ensure appropriate notices and an opportunity for competition. Advertisement is not required, and the purchase may be made in the open market in any of the following cases:
C. In comparing bids and making awards the authority shall give due consideration to such factors as: