A method of comparing and analyzing expenditures and savings for a first and a second time period includes a first step of receiving consumption data, expenditure data and market price data for the first and second time periods, a second step of calculating data representing a change in savings from the first time period to the second time period, based on differences between the market price data and the expenditure data for the two time periods, and a third step of outputting the data representing the change in savings from the first to the second time period. The consumption data represents a type and an amount of a commodity consumed during a given time period, the expenditure data represents an actual cost paid for the commodity consumed during that given time period, and the market price data represents a market price of the commodity consumed during that given time period.