Agencies may authorize an employee to use other than coach class accommodations on common carriers as long as—

1. (a) The non-Federal source makes full payment for such transportation services in advance of travel;
2. (b) The transportation accommodations furnished are comparable in value to those offered to, or purchased by other similarly situated meeting attendees; and
3. (c) Travel meets at least one of the conditions in § 301-10.100 of this subtitle.