I'd keep the rc8 for sure expecially if its nitro. I love my losi 8ight 2.0 buggy and i'm sure you will love the rc8, both are fairly close in terms of overall setup. The jato really isn't for most people as you probably already know or are just finding out. It isn't very competant in dirt and onroad its below average compared to most touring cars. But the claim on the side of the box of 70+ mph is what makes them sell.
For traxxas stuff i'd recommend going to the traxxas forum as their stuff does pretty good there. I tried selling my revo platinum here last week for what amounted to a steal and didn't get any offers. I was parting with basically $600 worth of stuff including ove $200 in replacement parts and didn't get any action here. Over there i at least had offers on the parts and the truck. I ended up just selling it on ebay. I couldn't believe not 1 person would take the whole lot for $350 shipped, which imo is highway robbery. I mean i paid $375 for just the truck only 3 week prior with no radio, no extra parts, nothing. One guy was offering $300 shipped and on top of that he wanted me to throw in a spektrum dx3s radio and telemetry equipped rx. I pretty much told him to take a hike and threw it up on ebay for a quick 24 hour auction. It sold for $455, so i was happy. I then turned around and stuck the money in a race roller losi 8ight-t 2.0. All in all a good trade imo.