most likely cones. Concrete walls arent cheap to put up.

Just find a truck and rent a U-Haul dolly trailer. I know its not going to be cheap either. I suggest you make your own. They're not that hard to fabricate. A strong short steel frame with a tounge (spelling) If you're into the drifting scene and travel once awhile, I say youre better off making one. And rent it out to some friends when not in use. Or just look in Bargain Trader, they might have it.