What a great thing to do for your instructor. I have had some people offer me money, not $100, but still the offer was made. I tell them this. I am just repaying the help I got when I started. When you get to the "Old flying guy" stage, remember the help you got and offer it to the new people. I never have and never will take money for teaching a person to fly. But there is nothing wrong with accepting a offer, thats just me. Just to help a person solo in a safe plane and under his/her own control is payment enough. And it's really cool when after a few months, people say that the student is flying better than the instructor. Not a slam on my flying ability, just a pat on the back for a good job teaching. Instructors....got a love em! Jeff