Located here [1] is an article about a program designed to simulate artifical electricity markets. In a software program called Power Agents, consumers and producers are modeled as "optimizing goal-seeking" agents in a an artificial electricy distribution market. Consumers respond to price changes by maximizing their subjective valuation of the electrical services provided.

A similar program could give us the very basics of what we are looking for--one could see how independent, utility-maximizing agents respond to a change in price of certain foods, because of, say, a change in where the food comes from.