My son is 13 years old, and has some experience riding his friends 1984 kd80. He pushes the bike as hard as it can go. He saved up about $900 for the bike itself. He will mostly be using it for trails, but occasional high rpm rip. he is 5'7" and growing rapidly. He wants something he can ride comfortably but grown into. He can do basic maintenance himself, but would prefer a lower maintenance bike. Right now he is leaning towards a kx100, xr200, or a drz200. All help is appreciated!