Let it be known that good screen printing is an art. You can't just buy the equipment and print good quality shirts at the start.
I agree with everyone... I'd leave it to contract orders at the start. Or do what I do and never plan on buying the equipment. I would rather sub-out. Do you realize how many more orders I can process a day by doing the design, paper work, and phone calls vs. design, paper work, printing, folding, etc. It more than pays off in the end!