Or is it one or the other? For example we need to have the price of the product be a factor in the shipping price for our guitars, which it is now, but for our amplifiers we sell on our site they need to go by weight instead of price. I am new to all of this, I just took over the website here and have no experience working w/ the cart code but this is a problem I know that needs fixed. Any help would be appreciated. Thanks.