We recently passed on a 50k job because they "knew a guy that could do it for less." To that my Dad said, "Well then you should definitely have him do it." With a smile no less and we left. This was 2 months ago, the guy still isn't done and it looks like crap, is severely under-equipped to do it. We figured 2 weeks to do the entire project had we done it.
Thanks but no thanks on bartering, this isn't a pawn shop.