I order shirts from
Teefury every now and then. They post a new print every day that is available for only 24 hours. The price is usually $9 or $10 + s/h.
The print is often quite geeky, related to tech or pop culture in some way.
I like American T-shirt sizes, because they are tall enough. European sizes are made to fit short, fat Italians (think Danny De Vito) and not tall Northerners like myself. Compared to the usual price of a printed T-shirt over here (usually
starting at $25 for the cheapest print), it is
still relatively cost-efficient for me including overseas shipping.