There are several Cafepress competitors...the best-reviewed one I see (from an admittedly cursory bit of "glance at it" research) is Printfection, however there is also ShirtCity, CustomInk, etc. (Sorry...not enough posts to put the links here for you, but just put a dot-com after each one and you'll get there.)

CustomInk pays a straight 10% commission on any sales made, while Printfection, ShirtCity and CafePress all let you determine the profit per unit by setting the retail price.

Hope that helps...at least a little bit.