True Value of working on old Mopars

I've been working on this one for a guy I met at a car show. I enjoy it, and we have become friends. He pays me and buys me lunch. It's not a huge amount, but extra cash never hurts. I never asked, and he can afford it, so I accept it. I can really use it with my current situation, but if he couldn't afford to pay me, I'd help him out anyway.