Computer simulation is finding a role in an increasing number of scientific disciplines, concomitant with the rise in available computing power. Realizing this inevitably requires access to computational power beyond the desktop, making use of clusters, supercomputers, data repositories, networks and distributed aggregations of these resources. Accessing one such resource entails a number of usability and security problems; when multiple geographically distributed resources are involved, the difficulty is compounded. This presents the user with the problem of how to gain access to suitable resources to run their workloads as they need them. In this paper we present our solutions to this problem, a resource trading platform that allows users to purchase access to resources within a distributed e-infrastructure. We present the implementation of this Resource Allocation Market Place as a distributed multi-agent system, and show how it provides a highly flexible, efficient tool to schedule workflows across high performance computing resources.