In economics, a price system is a system through which the valuations of any forms of property (tangible or intangible) are determined. All societies use price systems in the allocation and exchange of resources as a consequence of scarcity.

A free price system or free price mechanism (informally called the price system or the price mechanism) is a mechanism of resource allocation that relies upon prices set by the interchange of supply and demand. The resulting price signals communicated between producers and consumers determine the production and distribution of resources.