My experience has been that the dealers consider the used coaches as numbers out of the Blue Book. When considering the trade-in value, I have been asked if the coach is in "good condition", otherwise they have not seen the used coach until I bring it in to move our stuff from the old coach to the new coach. That will take three full days, so arrange with the dealer to have a quiet place in the lot to do the move. Be sure the new matress in the new coach is the one listed on the build sheet.
Also, I found that the dealers do not care that you added $10,000 worth of really cool stuff to your coach. So make a point to take out any add-on that you can install in the new coach. Also, the new coach will probably be missing electrical adapters, dump hose fittings, etc., so take all of that from your old coach. I saw my old 2005 Admiral for sale about a month later and they had taken off and cleaned out everything that I had left for the new owner.
Luke and Kathy & Charlie kitty, Morro Bay,CA
2007 Diplomat 40' SFT
2013 Honda CR-V "More is the enemy of enough."