The outcome of any auction sale is dependent upon a variety of interbehavior dynamics, which are either intensified or diminished according to the number of bidders involved. Two live auctions were studied and significant relationships were found between the number of bidders and bid range, starting bid values, and winning bids. The least competitive bidding occurred with three bidders. When there were four or more bidders, winning bids were likely to exceed starting bids. Strategies for participating in live auctions are discussed. © 2003 Wiley Periodicals, Inc.