In that situation, I would personally try to estimate the number of shirts you'll be handling and work from there to figure how long you want it to take for you to get a return on your investment. What will the market bear there? Are you in competition with local screen printers and what are they charging?
With the laser transfer, at least around here, I can be competitive with screen printers for short runs - up to about 20-24 shirts. Beyond that, up to about 36 shirts, we're at about the same price point. Beyond that, the gap between screen printer and laser transfer makes screen printing more economical for the customer. That is, assuming that they want something that works well with screen printing (i.e., 3 color printing).
While the screen printing tends to be labor intensive on the front end, building the screens, etc., Laser transfer is labor intensive in the actual production itself. Wait until the first time you get a request for printing on front, back, and sleeve on a dark shirt. A single screw-up on the 3rd print destroys the shirt (and along with it, the money you spent on the front and rear transfer).
Find out what your competition does .... figure how much you spent on your initial investment .... price yourself competitively with the screen printers at a run of perhaps 12 shirts but with the advantage of quicker turnaround time.
Good luck!
