(1) A sale under this part must be for cash or on terms that the board of county commissioners may approve, provided that at least 20% of the purchase price is paid in cash. All deferred payments on the purchase price of any personal property sold must bear interest at the rate of 6% a year, payable annually, and may be extended over a period of not more than 5 years.
(2) A sale may not be made at public auction or to any school district without public auction for less than 90% of the appraised value.
(3) The title to any property sold under the provisions of this part may not pass from the county until the purchaser or the purchaser's assigns have paid the full amount of the purchase price into the county treasury for the use and benefit of the county.