When determining the opening bid, a county takes into account if the property is homestead. If it IS, then 1/2 of the Assessed value of the property is added to the Opening Bid. That shows BIDDERS what they need to start the bidding. However, for the purposes of collecting surplus after the auction, that ‘1/2 of the assessed value’ also goes to the previous owner/lienholders/mortgage company (whoever is claiming the surplus).
No matter what the starting bid and ending bid is, the county only recovers their past due property tax and any fees they incurred in order to auction the property. The rest is surplus.