I think the way cafepress works is
a) you create a design
b) you create a rate for the products using that design, that is the base rate that cafepress charges PLUS your profit
When someone on cafepress says "all profits go to Ron Paul" it is the profits that go to Ron Paul, which is the price of the product minus the base rate.
We could probably do better if we find an RP supporter who owns a printing company, and who can really get us some really good discounts so that we can all get bumper stickers, T-shirts, business cards, flags, etc.