Alana - have you looked at cafepress -
Custom T-Shirts, Unique Gifts, Posters, & Personalized Mugs | CafePress . You upload your designs and they print them on a variety of items - all chosen by you. You get to set the price you want for each item, and they do all the production and shipping. I used them a few years ago for a non-profit I was working with and we sold quite a bit hassle-free.