File sharing networks are among the most popular applications of Peer-to-Peer (P2P) technology to date and have been widely studied in terms of the performance, behavior, topology and other properties. A persistent theme throughout this research has been the evidence that many P2P file sharing systems rely on the presence of altruistic users, who provide files, network capacity or some other goods without obvious personal gain to work and are potentially damaged by the presence of too many free-riders (users who consume resources but do not provide to others in return). In this paper we will explore the use of simple market mechanisms for P2P file sharing which function without the need of altruistic users considering the conditions under which such markets may be viable.