All screen printers have minimums. That's just how it works.
One other thing to consider is that your pricing from the screen printer is going to directly depend on how many t-shirts you print of the same design in the same job.
So if you only print 50 t-shirts of the same design, that's going to cost more than if you printed 100 t-shirts of the same design (in the same order).
Would the bay area of California work? If so, I'd recommend ForwardPrinting.com