The research to the grid economy is gradually becomes a new hot spot with the grid technology development. In recent years there are also some remarkable results in this area of research, for example the middleware, Grid Architecture for Computational Economy (GRACE), however, in the research process, the GRACE has been discovered that the module of pricing fluctuation is not explicit. In grid economy architecture the fixed prices of resources will cause a problem whereby the profit to the providers will be significantly reduced, additionally, this will cause the reduction of the success ratio of tasks accomplishment. This paper presents a new kind of pricing fluctuation module called Resources Pricing Fluctuation Manager (RPFM), as part of GRACE architecture. It also presents the detailed inner architecture and makes a discussion of each part of RPFM. At the end, the paper shows the significance of the RPFM module through simulating experiment.