I had a few questions before I sign up, or even try to test your very cool cart ...
1. does your cart sell more than 1 item at a time ?
2. Can your Tax / shipping calculator be added to more than just 1 state like mine is 7.25 but there is a ton... more.
3. The way pay pal sets up there check out page you don't even see ADD YOUR zip so the tax is added ?