All sales and leases made by, or on behalf of, the State of Alabama, or any department, board, bureau, commission, institution, corporation, or agency, of real property or any interest therein owned by the State of Alabama having an appraised value of more than twenty thousand dollars ($20,000) shall be made by free and open competitive advertised public auction or advertised sealed bids to the highest bidder.
Ala. Code § 9-15-71 (1975)