With the increasing importance of Electronic Commerce across the Internet it is becoming increasingly evident that in a few years the Internet will host large numbers of interacting software agents. A vast number of them will be economically motivated, and will exchange a variety of goods and services. It is therefore important to consider the economic incentives and behaviours of economic software agents, and to use every available means to anticipate their collective interactions. This paper address this concern by presenting a market simulator designed for analysing agent market strategies based on a complete understanding of Buyer and Seller behaviours, preference model and pricing algorithms.