Some dealers just don't want your trade so they low ball you knowing they can wholesale it out to another guy and make a small profit.
In addition, I think people are unrealistic in their expectations sometimes.
They want 25-30% off MSRP of the new coach and close to low NADA on the trade.
If you want that 30% off the new one you better sell your existing coach yourself. Don't want to do that do you? Why not? Because its PIA to sell a semi expensive motor home on the secondary market for anything close to NADA. Yet you expect the dealer to pay that and try to resell it for a profit? Come on.
Bottom line in trading is you are using the dealer because its convenient. You can still get pretty good deals when doing it if you're persistent and use a high volume dealer but in the end you aren't getting the "best" deal because the dealer has much more risk.
They don't want your POS motor home sitting on their lot depreciating and if you want them to take that risk you pay for it. End of story. Many dealers DO NOT WANT YOUR COACH.