To me its not worth it. I have an rtr chassis on my buggy and a race tuned one on my truggy, and imo its just not worth the money. You can find them for $40-50 on ebay if you keep an eye out. Even at $40-50 i don't think its really worth the money.

I'm running a rtr buggy with a few upgrades and i can keep up with the ones running race rollers at the local track. Its more about driving then who's got the best parts. Just spend the extra money on fuel and practice. $50-90 worth of fuel and practice will get you much further than throwing a new chassis on your rig, that i can promise.