boys are really interested in flying you need to read this book. "BOYD" by Robert Coram. It's quite eye opening and actually sorta astounding I think.
I took some lessons once in 1965. This guy had an old Aeronica Champ and he gave me lessons dual for guess what? $8 per hr. Unbelieveable. I remember he was 58 years old at the time and had been flying since he was 16 years old.