The director may request bids and award contracts for construction work requiring the contractor to furnish all equipment, labor, materials, and supplies for each particular contract or project, or requiring the director to furnish and provide the contractor with materials and supplies as the director may elect. If the director elects to provide materials and supplies for any project or construction work, the director shall notify the office of management and budget of the fact that the director has elected to furnish the materials and supplies. The office of management and budget may either exempt the purchase and allow the director to request and let bids and make the purchase, or the office of management and budget may handle the bidding and purchasing through its central purchasing agency. Either the office of management and budget or the director shall request proposals or bids for the total and aggregate of the materials and supplies for any and all projects or construction work according to the class, type, and nature of the materials and supplies and may award a contract or contracts therefor upon a basis deemed efficient and economical, whether upon the basis of delivery to the construction project directly     or to a central storehouse or storehouses maintained by the state. The materials and supplies purchased by the office of management and budget or the department of transportation may be delivered to the project or construction work without expense to the contractor doing the construction work or may be sold to the contractor at cost and made to constitute a part of the construction cost, as the director may elect.