that is the KEY factor...what about maps...the power commander is a great tool...but is useless without information to run it...and realistically needs the LCD screen and memory to tune it in...then it needs the af gauge, then it needs the timing...now you are talking serious cash...
but once dialed, I think it is absoutely the best programmer on the market...and if you have access to dyno and programs...then it is worth it, but if you are just reselling...not much value add IMHO...
and yes, I will delete this post or amend it if you are truly giving a great value add...