I am more than happy doing bike work for others, as long as it is something I know how to work on. I always barter for work, I usually ask for bike stuff in return. But I have traded for other stuff too. One neighbor is notorious for taking advantage of others. So I fixed her kid's bike, no big deal. I just told her to find me an adult racing bike, in decent shape in return and don't spend much on it (she hits the garage sale circuit hard). Two years later, in my driveway was a Cannondale racing bike. Nice. Win/win.