The sales tactics are similar for automobiles and RVs, the difference is that typically there is only one dealer that carries that specific RV in a given area where they might be 5 dealers that carry that specific automobile, if you don't play the game a bit, you'll end up traveling to purchase that particular rig.
It always boils down to out the door price, if they want to inflate your trade-in so you can purchase at or near MSRP, the final out the door price may turn out to be a good deal. Best scenario is to unload your current rig first as we tend to over-value our rig's worth, either way the dealer will always hit their profit margin. Of key note is that NADA pricing is not indicative of the current market value.
They need to make their profit in order to stay in business, and we all don't want our purchasing dealer to close up shop in case we need warranty service or parts down the road. Many choose to go where the best deal is for their particular RV, traveling extensively to pick it up, and maybe after it's all said and done they have saved a few dollars. The risk is if the rig needs warranty service on some serious issues and local dealer decides to make you wait or not provide service at all.
It's important to do as much research once you have decided on a particular unit, but stating you have the real low down will not always work in your favor. People will always tout the great deal they made and that is exactly what the dealer wants us to think.
Doing the research and playing the game wisely will turn the tables where you do get the better deal and the dealer only makes the bare minimum profit required, plus if the dealer is customer service oriented you can have the confidence that they will take care of any issues should they arise. A win-win situation for all because getting a great deal from a crappy dealer only leads to headaches down the road.
Enjoy your new rig!!!