Abstract: An item-selecting device includes item data retriever, item selection receiving means, item combiner and output means. The item data retriever retrieves individual price information for items offered as single items and set price information for items offered as sets of items from an item information storing part. The item selection receiving means receives item selection information of a selection of items selected by a user that includes at least one single item and at least one set of items. The item combiner regroups the selection of items into at least one combination of items consisting of the same items as included in the selection and choosing a combination offered at lowest total price by referring to the individual price information and the set price information. The output means outputs the result obtained from the item combiner.