1. An interactive, computer-implemented system for negotiating purchases of goods and/or services, comprising: a database storing merchant character data which simulates a human merchant having predefined behavioral attributes; interface means for enabling a customer to input data relating to the purchase of particular goods and/or services; and a database engine which utilizes said merchant character data and said data inputted by a customer to generate responses to said data inputted by said customer according to said behavioral attributes; whereby the occurrence of a sale for said particular goods and/or services at a specific price is determined as a function of customer replies to merchant responses and said merchant behavioral attributes.