for what you're going to end up paying, just get more people and then own the software/accessport for pro-tuning. then you can have people constantly pay you. shoot...if you got a few more, i'll buy it and then have you guys pay me. done.
if you had 13 people (which I'm sure i could add a couple of local guys) at 450...the unit would be 100% paid for, and yours to keep. just trying to help.