Payment method decision engine

A computerized system and method that enables identifying the best payment currency for a product or service is disclosed. Payment currencies include cash, reward programs and the unit or currency in which reward programs are denominated, and combinations thereof. A single product search request initiates searches of multiple payment currencies. Availability, discounts, prices, comparable costs, net values and relative values are determined and/or calculated per each payment currency. Comparable cost, relative value, or other criteria, may be used to determine the best payment method, that is, the lowest cost in a common currency, such as cash. Determination of the best payment currency is accomplished in "real-time" and has an advantage of leveraging quantitative and qualitative analysis in its determination. In addition, the search may be personalized by adding information unique to each user.