It depends. I generally am open to non-financial compensation. I’ve been known to work for beer or accept IOUs with the expectation of favors in kind. I think we’ve all done things for friends that have done things for us, right?
If we put a dollar figure on my time though, it would depends on the skills I am expected to use and how long I am expected to use those skills for. Look up the hourly rates for PC repair technicians, machinists, and journeyman-level electricians and you’ll find my rates run pretty close to “fair market” prices, though a little lower so as to remain cost-competitive.