Advice on how to trade up on a Montana

[RKassl]

I have purchased many vehicles with trades over the years, but this may be the first time trading up on an RV. I went to my dealer and the salesman who sold us our current 2005 is still there. When we negotiated prices he never once looked at our 2005 Montana which is in wonderful shape and loaded with many upgrades over the years. How do I know if I am getting a fair trade value? My trailer could be in horrible condition and he would never know it? I realize that there is a huge gray area for pricing a trailer but I am not satisfied that he is doing me any favors.

Any advice on what to do different if we restart negotiations or if I go to another dealer? How do you protect your current investment against a new Montana?

Any advice would be appreciated!

Thanks