People often attach a higher value to an object when they own it (i.e., as seller) compared with when they do not own it (i.e., as buyer)—a phenomenon known as the endowment effect. According to recent cognitive process accounts of the endowment effect, the effect is due to differences between sellers and buyers in information search. Whereas previous investigations have focused on search order and internal search processes (i.e., in memory), we used a sampling paradigm to examine differences in search termination in external search. We asked participants to indicate selling and buying prices for monetary lotteries in a within-subject design. In an experience condition, participants had to learn about the possible outcomes and probabilities of the lotteries by experiential sampling. As hypothesized, sellers tended to terminate search after sampling high outcomes, whereas buyers tended to terminate search after sampling low outcomes. These differences in stopping behavior translated into samples of the lotteries that were differentially distorted for sellers and buyers; the amount of the distortion was predictive of the resulting size of the endowment effect. In addition, for sellers search was more extended when high outcomes were rare compared with when low outcomes were rare. Our results add to the increasing evidence that the endowment effect is due, in part, to differences in predecisional information search.