So here's a good question..
I added a Pull-down Menu for a product which is a 6oz. tube of lotion, to give the option of choosing the 1oz. tube.
it looks like this..
6oz. Tube
1oz. Tube ($2.84) ;-6.87
the problem is the weight is different. Is there a way to also change the weight, so it recalculates the shipping costs.. clearly this will only be an issue when a costumer orders enough product to made a difference in total weight