In order to produce the highest return for the sale of personal property, the Purchasing Agent may select from the following sales methods the one which, in the Purchasing Agent's judgment, will yield the greatest return under the circumstances of each sale: competitive sealed bids, as prescribed in Section 10A-112; competitive spot bids sale; competitive auction sale; trade-in; or exchange for goods which are of current need. The Purchasing Agent may negotiate a sale when the above methods are inappropriate or have failed to produce a fair price or value. All agencies shall submit to the Purchasing Agent, at such times and in such form as he may prescribe, reports listing stocks of all personal property which are no longer used or which have become obsolete, worn out, or scrapped. The Purchasing Agent shall have the authority to transfer serviceable surplus commodities between agencies in lieu of filling requisitions for the purchase of new and additional stock of the same or similar articles. Notwithstanding the provisions of Subsection (a), upon certification by the Purchasing Agent that the property is not needed by the County, the County Executive, by Executive Order, may authorize the donation of one car per year to the Prince George's County Board of Education to be used as a door prize for the purposes of encouraging students to participate in alcohol free and drug free school functions.