If your kid is a motorbike enthusiast, then you will probably want to get him/her a safe and powerful bike. With so many models in the industry to choose from, you may end up getting the wrong bike.

Same as phoenix_rizzen - I bought a Dillenger kit here in Oz for $900 (about US$600). Very similar, drop in front wheel (with an extra torque arm to support the front fork). It's heavy, but works ...