Section 1. Be it enacted, &c., That whenever any department, board, or commission of this Commonwealth shall put into the possession of the Department of Property and Supplies any personal property of this Commonwealth as "unserviceable," and at the same time requisition the Department of Property and Supplies to furnish or order said department, as purchasing agency, to purchase new property of a similar character to replace the unserviceable property delivered as aforesaid, the Department of Property and Supplies, with the approval of the Board of Commissioners of Public Grounds and Buildings, shall endeavor to induce the person, partnership, or corporation from which such new property is purchased to accept said unserviceable property for, or on account of, the purchase price of the new property purchased in accordance with such requisition or purchase order: Provided, however, That such unserviceable property shall not be delivered for, or on account of, the purchase price of such new property at a lower valuation than the price which such unserviceable property would bring if sold in the open market for cash. To the extent that advertising may be necessary to enable the Department of Property and Supplies to determine the market value of any such unserviceable property by offering it for sale for cash, said department is hereby authorized and directed to advertise as now provided by law in connection with the sale of unserviceable property of this Commonwealth.