Ever think of getting a 250r? for about 3500 you can have a sweet R with an aftermarket frame, LT suspension, one hell of a motor, and all the goodies. Its no shee in the motor department, but it still has that 2-stroke snap, and its a do it all quad for sure. Rebuilds and parts will probably cost less, and I think you'd have a lot more fun on an R, being able to handle trails and the mx track as well as your buddies who have the 450's. Check out R's on ebay to get an idea of what theyre going for. I think I saw some beautiful R's on the quadzone forums, under the full race classified section. Good luck,
Brian
Edit.... Just read you got a 450. Congrats