bwnbwn - 5:47 pm on Sep 9, 2013 (gmt 0)
dickbaker I ran into this issue when I had my ecommerce store. The method you use won't work if there are multiple items added in the cart and you see the problem.
What I did was use weight but you can't use that so maybe when multiple items are added in the cart just give a discount of the average shipping cost of your items.
if two items are added then give a 8.00 discount, if three are added give a 16.00 discount and so on.
Your really limited since weight isn't in the equation, but by giving the multiple item discount it might just get more items added into the cart.
Just my thought might or might not work for you since I know nothing on your items and or weight per item.