D.C. Code § 1-301.110b: Use of exchange allowances or sale proceeds to purchase similar items.

In purchasing motor-propelled or animal-drawn vehicles or tractors, or road, agricultural, manufacturing, or laboratory equipment, or boats, or parts, accessories, tires, or equipment thereof, the Director of the Office of Contracting and Procurement or his duly authorized representatives may exchange or sell similar items and apply the exchange allowances or proceeds of sales in such cases in whole or in part payment therefor.