Whenever any elective county officer has under his jurisdiction or control any personal property belonging to the county which, in his judgment, is of no further use to the county, he may, with the consent of the board of county commissioners, in the name of the county, sell such personal property. Whenever any such official has any personal property belonging to the county under his jurisdiction or control which, in his judgment is obsolete, worn or damaged so as to require replacement and is of greater value on a trade in or exchange for replacements than upon the sale as above permitted he may, incident to purchase of such replacements and with the consent of the board of county commissioners, trade in or exchange such personal property and apply its trade in or exchange value on the purchase price of replacements. If the purchase of such replacements requires calling for bids, the call shall include bids with proposed allowances for such obsolete, worn or damaged property. All cash received from the sale of personal property must be turned in to the county treasury.