Wis. Stat. § 24.12: Forfeit for failure to pay.

Every purchaser of any lot or tract at any sale under s. 24.11 shall pay the amount of the purchase money required by the terms of sale to be paid as provided in s. 24.11 (1). If the purchaser refuses or neglects to so pay, the lot or tract bid off by the purchaser shall again be offered for sale. The purchaser shall, for refusing or neglecting to pay, forfeit $25 for each lot or tract bid off by the purchaser, which the board shall, in the name of the state, cause to be immediately sued for and collected, and, when collected, paid into the school fund.