In this article, we advocate more extensive use of the benefit function in specifying price-dependent or inverse demand models. We demonstrate how duality theory may be used to establish the interrelationships between the Marshallian (or Hicksian) inverse demands and Luenberger's adjusted price functions, allowing estimable inverse demands to be derived directly from a benefit function. We estimate two systems of inverse demands for Japanese quarterly fish consumption. Results indicate that the procedures and methods employed here appear promising, and may prove beneficial for quantity and welfare analysis when modeling systems of inverse demand functions. © 2009 Agricultural and Applied Economics Association.