Make sure that....
you use your name, Maine Sail, in the product name as you do have name recognition in many forums. I also think a simple name is better ( Butyl Tape ) . You could try Maine Sail's Best Butyl Tape. When asked for the good or better, just respond that the Maine Sail name is nottin' but the best.
As far as shipping cost, it is what is it. It's the handling fee that would get to me. That should be in the cost of the product. Until you have a online store, get a PayPal account. It makes it easy to spend money
Oh, Put me down for 2-3 rolls. As said before, ziplock baggies in a padded envelope or priority mail box would be fine.