When I think stadium truck I think 1/10th scale 2wd like an Associated GT for example. Are you thinking of an 1/8th scale truggy?
There is the Hot Bodies 1/8th scale Lightning Stadium Pro RTR Truggy (Ready to Run) for around $520-ish. I don't know if you need a starter box or not tho.
The Traxxas Revo 3.3 is a good 1/8th scale monster truck. It's right at the $525 mark or so too as a RTR. The Revo 2.5 is right at $400 RTR. I think the Revo comes with a pull start engine so you would not need a bump starter box. If you are just planning to bash the Revo 2.5 would probably be great. Huge tires that can go over just about anything hehe.
I've never owned either of these but I know the Revo has a huge aftermarket parts offering. Oh yea prices are at www.towerhobbies.com
, you may be able to find cheaper