A method of executing a transaction related to the purchase of fuel. A contract is entered into by a purchaser with a card service provider or financial institution for a certain amount of fuel at a fixed or capped price offered over a predetermined duration. The fuel is purchased from a retail merchant. A payment is made or received by the purchaser depending on the difference between a prevailing retail index price and the fixed or capped price. A premium may be paid for entering into a capped price arrangement. The fixed and capped prices may be related to a retail index price at or before the time the contract is entered into. In another embodiment, the method includes receiving retail price index data for fuel sales and determining fuel sale contract criteria, with a fuel sale contract proposed for a purchaser.