Your new, and want to spend 300 bux. You can get a GT ready to run for 270 at Tower Hobbies
A big buggy like that would be nice, and fun. But they have a ton more parts to keep in working order. That buggy above I didn't check, but can you get all the parts for it at the link above? I've seen other cars being sold at low prices that you couldn't even find where to get parts. The GT is reliable, very durable, and also very easy to work on.
Really depends on what you are planning on doing with it though. Do you eventually want to race? Or don't ever plan to and just want to bash around? Do you have friends to do that with? What do they run? It's nice to have the same brand as the guys you run with so you can swap parts. If you're planning on running in grass or super rough stuff, maybe a monster truck would be better. They can go through anything pretty much. But again, they are harder to work on. And have many more parts.