§ 31-a. Purchase through the state division of standards and purchase in the office of general services by certain not-for-profit corporations. A corporation, incorporated under the not-for-profit corporation law of the state of New York and approved by the federal government as a recipient of federal funds for the acquisition of equipment to provide transportation services to the elderly and/or handicapped, may make purchases, upon the written approval of the department of transportation, of special vehicles and/or radio equipment pursuant to the terms of contracts let by the state division of standards and purchase in the office of general services subject to such rules as may be established from time to time pursuant to § 163 of the state finance law which may establish limitations with respect to commodities and impose such other appropriate conditions upon purchasing as deemed necessary by the commissioner of general services in order to protect the state's own purchasing interests; provided that each such purchase shall have a cost of five hundred dollars or more and that said corporation shall accept sole responsibility for any payment of such cost due the vendor.