What kind of quantity are you talking about? A local silk screen shop should be able to turn 'em around for about that price, provided you can pick them up (saves a lot on shipping), you're happy with decent but not fancy shirts (think Hanes rather than American Apparel), and you've got just a couple colors and a reasonably high number of shirts to spread the setup costs (silk screening setup costs are per-color, about $50 around San Francisco, I can't imagine it'll be any more than that anywhere else).