The property duly advertised must be sold, by the person officially charged with the collection of delinquent taxes, at public auction at the courthouse or other convenient place within the county, if designated and advertised, on the advertised date for legal tender payable in full by cash, cashier’s check, certified check, or money order on the date of the sale. If the defaulting taxpayer or the grantee of record of the property has more than one item advertised to be sold, as soon as sufficient funds have been accrued to cover all of the delinquent taxes, assessments, penalties, and costs, further items must not be sold.