I am going to try to get into the office tomorrow with the fast wifi, my home stuff is too slow and keeps aborting the upload. 250's are fun but tough as a beginner bike especially on an MX track. The 250's are about corner speed and reving the motor to make power. When you come out of a turn and need grunt to clear a jump it's way easier to do that on a 450 than a 250. The compromise is the KTM 350, either way, it's much easier to de-tune an MX bike for trails (lower gearing, fly wheel, clutch....) than to take a trail bike and make it MX capable. The closest MX capable trail bike now is the KTM XC line, but once you get into low level competition speed you'll start to exceed the suspension. Honda and Yamaha have trail models but the suspension isn't up to snuff for light MX duty, you'll be blasting through the stroke and bottoming out the suspension. Just so you know what you're getting into, riding fast in the dirt is much more tiring than fast on the track, the only rest time I get in the dirt is in the air, the rest of the time your standing to absorb bumps with your legs, or moving to aid turning, braking and acceleration. Watch the pro guys and you'll see very little time sitting, usually to enhance rear wheel traction (sitting way back on seat) or to seat-bounce jumps (sitting to add more preload to rear suspension to increase height and distance on jumps), rest of the time they are standing or moving on the seat side to side. In reality its great physical training for track day riding.