Starting to design and market T-Shirts?

I’ve recently been thinking about designing and selling t-shirts. There are two websites that I have in mind as a “starting point”. These sites are Threadless and Zazzle, and each has their advantages and disadvantages. Threadless offers a large sum of money if your t-shirt is printed ($2,000), and another large sum of money every time it is reprinted ($500). However, your designs must be chosen by the Threadless community. With Zazzle, you don’t need to have your design accepted by any community, and can start selling the shirt immediately. However, The pay is low at $1 – $5 for every t-shirt sold. Which is the better route to go? Feel free to suggest any other options.