I personally would pay $100 and cover shipping for a soldered up Xbox 360 wireless controller today, in fact I would buy 2. I guess if a guy could sodder one together, say in an hour, he would be making $50 an hour, pretty repectable. If it takes longer naturally you would make less, but could argueably charge more. No real idea what "fair" would be but certainly worth a thought I guess.
Zeosstud