Hi guys! Just wanted to share my experience with the website
http://www.qwertee.com/ . They've got a new shirt on sale every day, and it's really cheap too! They often have very geeky cross-overs and their t-shirts have a really good quality. I've even seen some LBT designs (that have not yet been turned into shirts, although I'll keep you updated when they are!). You can always get one shirt for 24 hours for the cheapest price, and then the day after that for a slightly higher price (in case you missed out!), but they go out of print pretty much forever afterwards.