A common practice among large retailers is the low-price guarantee, rebating consumers if they find an identical product cheaper elsewhere. This provides consumers with some level of comfort in their purchase decision. A similar low-price guarantee is provided by numerous service industries that allow reservation of capacity, yet do not penalize the consumer for failure to keep that reservation-examples include hotels and car rental. Given that a consumer is not required to keep the reservation, they may make another reservation, either at a competing firm or the same firm, if future prices decline. The increasing availability of pricing information on the Internet affords consumers the opportunity to be more strategic in their purchasing behavior. As consumers, we are able to quickly and easily check prices from numerous service or goods providers. The ease of price information potentially makes these guarantees very costly to the service or good provider. We analyze the implied costs associated with these guarantees by making analogies to financial options. Motivation for this research comes from a large car rental firm, Dollar Thrifty Automotive Group Inc., that considered offering a low-price guarantee to all consumers that book a reservation though their website.