Sorry If I've not been clear. What I need is to have a customer select, 1 on the input page, they then click "add to cart", the cart page is displayed and the quantity 1 is displayed and the appropriate price is charged. But when they're on the cart page they may decide to change their order to 3 (with the dropdown list), click "update", and 3 should be displayed and the price will become thrice what it was.