Love this website. They sell one shirt per day until it sells out. Shirts are $10 the first day with free shipping, after that they're $15 until they fall off the sales chart never to be sold again. Upgraded shipping is $5 for overnight.
Each week they have a design contest and the winners get their shirts sold on Fri, Sat, and Sunday.
Here's the shirts I've bought so far (in no particular order):