The Office of Management and Enterprise Services Central Purchasing Division shall determine the fair market price of all products and services included in the procurement schedule and shall revise such prices in accordance with changing market conditions; provided, however, a change in price shall not be effective prior to the expiration of thirty (30) days from the date on which such change is approved. Approved fair market prices shall be reflected on State Use contracts and procurement schedules within thirty (30) days of approval and distribution.