Market price is an economic concept with commonplace familiarity; it is the price that a good or service is offered at, or will fetch, in the marketplace; it is of interest mainly in the study of microeconomics. Market value and market price are equal only under conditions of market efficiency, equilibrium, and rational expectations.

In economics, returns to scale and economies of scale are related terms that describe what happens as the scale of production increases. They are different terms and are not to be used interchangeably.