  Many models of market dynamics make use of the idea of conservative wealth
exchanges among economic agents. A few years ago an exchange model using
extremal dynamics was developed and a very interesting result was obtained: a
self-generated minimum wealth or poverty line. On the other hand, the wealth
distribution exhibited an exponential shape as a function of the square of the
wealth. These results have been obtained both considering exchanges between
nearest neighbors or in a mean field scheme. In the present paper we study the
effect of distributing the agents on a complex network. We have considered
archetypical complex networks: Erd\"{o}s-R\'enyi random networks and scale-free
networks. The presence of a poverty line with finite wealth is preserved but
spatial correlations are important, particularly between the degree of the node
and the wealth. We present a detailed study of the correlations, as well as the
changes in the Gini coefficient, that measures the inequality, as a function of
the type and average degree of the considered networks.
