you are going to have a hard time finding a place that does that small of a minimal, and regardless of how cheap the printing costs may be, you might discover its still expensive anywhere due to the fact that you are only printing 10 to 20 shirts.
I normally get shirts printed in bulk of 75 per print, the price per shirt ends up at a nice $4.20 per shirt (plus setup costs). At the range your looking at, you might be looking at 6 to 7 dollars per shirt haha.