When a resale is made, the county auditor shall notify the director of the department of administrative services, who shall thereupon charge the county with the full amount of the resale, except that when the lands are sold for more than the unpaid portion of the principal, the excess shall be applied to reimburse the county for the costs of foreclosure and the interest paid by the county to the state by reason of default of payment of same by the makers of the notes, previous to the time when the right of redemption has expired, not to exceed three years.