I analyze a dynamic model of concurrent bargaining in which multiple prospective buyers compete to trade with an informed seller. When the seller maintains confidentiality over buyers' past offers, buyers may engage in competitive ``price experimentation'': buyers risk early losses to subsequently acquire informational advantages over competitors and expect to earn future information rents. Due to price experimentation, the seller may benefit from maintaining confidentiality over past offers and restricting buyer entry. The model has implications for the strategic choice between auctions and negotiations, and for the common use of ``pre-qualification'' in asset sales.