For a car as merchandise specified by remote negotiation, a commercial transaction document such as an estimate, a contract, or a purchase order which decides an amount related to providing of the merchandise is prepared on the same system and stored in a database in accordance with an operation on a salesperson terminal by a salesperson (provider). A receiver such as a customer can browse (display) the prepared commercial transaction document by using a user terminal. The commercial transaction document to be browsed is provided as document data or a printing product.