SHOPPING LIST SERVICE

An interface is rendered on a user-operated device. A shopping list of items defined by a user is obtained through the interface. A store associated with the items is identified and a tax jurisdiction for the store. Each item of the list is checked in inventory at the store, a set of substitute items are identified for each item, and available promotions are identified for each item and each substitute item. A total price for the list of the items that includes taxes in the jurisdiction of the store and includes any promotion pricing is provided to the user through the interface. The user can interact with the list through the interface to evaluate scenarios where the original list and/or a modified list meets a budget defined by the user or select an automatically determined list that identifies a lowest priced substitute for each item until the budget is met.