All lands, now owned or hereafter acquired by the state for educational purposes, may be sold at the expiration of the present leases. The Board of Educational Lands and Funds shall retain all mineral rights in the land sold. Prior to such sale, the land may be appraised for purposes of sale in the same manner as privately owned land by a certified general real property appraiser appointed by the board and thereafter shall be sold at public sale at not less than the appraised value. When two or more contiguous tracts are under separate leases with different expiration dates, the board may, if it is deemed to be in the best interest of the state, defer the sale of any tract having an earlier lease expiration date and may offer the tract for lease for less than twelve years to coincide with the expiring lease of the contiguous tract, in order that the contiguous lands may eventually be offered for sale on the same date.