1. A method of conducting a transaction between a buyer and a seller over a global network with a computer system, the method comprising: (a) receiving a lower limit price for a product from the seller via the global network, the buyer being unaware of the seller's lower limit price; (b) receiving an upper limit bid for the product from the buyer via the global network, the seller being unaware of the buyer's upper limit bid; (c) the computer system comparing the seller lower limit price and the buyer upper limit bid; (d) if an overlap region exists between the seller lower limit price and the buyer upper limit bid, the computer system setting a price point for the product within the overlap region that is based on the lower limit price and the upper limit bid; and (e) if an overlap region does not exist between the seller lower limit price and the buyer upper limit bid, the computer system further processing the transaction without seller or buyer input by setting a theoretical price point between the lower limit price and the upper limit bid, wherein step (a) is practiced by additionally receiving an expiration relating to the product and by receiving a lower limit price range from the seller that varies with time to the expiration.