The prices depend on the product style you choose and country of delivery. When you view the graphics on products from within the Fatpaint editor, you'll see the prices for Zazzle products.
You can also check the prices by going directly to the product supplier website. See a list of all suppliers at http://www.fatpaint.com/products. Use this list if you don't intend on using the Fatpaint editor for making graphics, but just want to upload the images yourself to the supplier of your choice.