The Hyper 7 is head and shoulders a better RC than the others you mentioned. I'm guessing you want nitro? you already have other models, so I'm guessing you don't need it to be completely RTR? What parts are you willing to transfer from other trucks? Servos? Receiver?

There's a very good truggy for only $330...the Hot Bodies D8T (the buggy is even cheaper), which is significantly better again than the hyper 7, but it will not include engine, electrics or anything like that. The kit and an engine/exhaust combo would probably fit your budget, but then you need to find 2 servos, a receiver battery and a transmitter/receiver, though I expect you already have tx/rx.

Car: http://www.amainhobbies.com/product_...ion-Truggy-Kit
Engine: http://www.amainhobbies.com/product_...in-Start-Combo
Exhaust: http://www.amainhobbies.com/product_...ystem-Polished

It's a little over budget, but it'll be an amazing RC. Otherwise the Hyper 7 is a safe bet.

This is also a good option for cheap... http://www.amainhobbies.com/product_...-RTR-1-8-Buggy

Or this... http://www.amainhobbies.com/product_...Spec-RTR-Buggy