Except as otherwise required under AS 36.15.050, AS 36.30.322 - 36.30.332, and 36.30.334 - 36.30.338, when a state agency purchases paper, at least 25 percent of the quantity purchased must be recycled paper unless recycled paper is not available for the purchase or unless, after application of the procurement preference under AS 36.30.337, the recycled paper is more expensive than the nonrecycled paper.