A crucial goal for future Grid systems is to strive towards user-centric service provisioning. A way to achieve this is through the use of economics-based resource management. Currently, several models exist from among which auction- and commodity-based models are the most popular. This contribution will focus on the latter, and in particular on commodity markets, where the value of a Grid resource is determined by supply and demand. We propose some refinements to the application of Smale’s method for finding price equilibria in such a Grid market. We also extend the approach to substitutable goods. That is, we introduce ‘slow’ and ‘fast’ CPUs, two categories of the same type of good that are priced separately, but are strongly coupled with potentially strong shifts in demand. We show that Smale’s method can be adapted to handle this type of Grid resources market, and that price stability, allocative efficiency, and fairness are realized. c 2007 Elsevier B.V. All rights...