What type of tow vehicle do you have? Perhaps, if you share the ratings of the TV people might be able to give you some more ideas. I'm thinking a 97 Silverado 1500 by looking at your signature but, not sure as I see two listed.
As for the trade in, it's all a numbers game. NADA will give you a rough idea but, some dealers will give you full NADA value and not move on their over priced trailer. Other dealers will offer you fair value for your trailer and take some off of theirs. It really is tough to gauge but, I think NADA will give you a rough idea. It looks like somewhere in the $1500-1800 range but, again it all depends what you are looking to trade it in for at the dealer. Some of them like to play some pretty good pricing games.
2012 Keystone Sprinter
Still sticking around for the good people and advice.