During the auction, Warren is heard in the background saying 'going, going,' and when Nora stands up and motions to Sarah, he says 'sold to Nora Walker.' A new bid should have started another round of asking for higher bids, since the person it was going to might want to outbid Nora. If no other bid came, he'd have to give the warning of 'going, going' again before declaring the item sold to Nora.