This manuscript provides a framework for understanding the relative power of male customers in heterosexual prostitution exchanges. Drawing on insights from Giddens' structuration theory, as well as basic principles of social exchange theory, we describe how personal qualities, relationship characteristics, and larger structural inequalities intersect to affect power relationships between buyers and providers. Consistent with recent scholarship that documents the complex array of cultural and economic factors that affect the experience of female sex providers, we examine how those processes also shape perceptions of power among buyers. While acknowledging that sex buyers are unlikely to have accurate understandings of the motives and constraints experienced by sex workers, we observe that customers do not universally perceive themselves to have greater power in such exchanges and that larger structural inequalities are not directly translated into differences in power in buyers' dyadic relationships with providers. Further, we argue that the variety of contexts in which prostitution takes place and the diversity of individuals who buy and sell sex mean that power relationships between buyers and providers vary substantially.