The Director of Public Works is authorized to enter into one (1) or more standard purchase or requirement contracts duly let to the lowest and best bidder after competitive bidding for vehicle maintenance materials, equipment, services, and supplies that the Director of Public Works considers necessary to the operation of the Division of Motor Vehicle Maintenance, including but not limited to: shop supplies and shop equipment, vehicle parts and equipment, lubricants, fluids, tires, tubes, tire recapping, vehicle and equipment batteries, remanufactured power trains or sections, generators, generator parts, and labor, materials, and installation, if necessary, to repair or maintain existing equipment. Any purchase made under this section shall be made by the Commissioner of Purchases and Supplies and paid from the annual appropriations made for this purpose.