Disclosed is an Internet-based method that enables users to search and browse for information (such as price) about a plurality of items (such as books) available for sale on the Internet, compare prices for the items individually or considered as a package, and optimize the package price. In a preferred embodiment, the invention searches for the lowest price and second lowest price for the desired items from Internet Web sites and databases, records the data in two matrices, and employs algorithms that implement certain set operations, including Cartesian product and set union, to optimize the result for all items.