Where can I get cheap sport shirts?

Not like authentic team jerseys, just a shirt that has a logo or something, something to show that the guy wearing it supports the team. I'm talking cheap like 5-10 dollars maximum. I can check the thrift store constantly, there's one right down the street from my house, but there are no guarantees that I'll find anything at all. I need like 5 of these for a play and idk what the budget is quite yet, it;'s not for several months, but you can't start planning too soon.