Worked for a couple of RV dealers and the markup was generally 40% or more. However, with several of the brands, the MSRP was set by the dealer, so beware of the numbers. If there is a particular rig that you are dickering with, look on the data plate to see when it was mfg'd. If it is more than three months old, they should take way less--don't be afraid to point this out to them, especially now at the end of the model year. As far as what you are getting for your used rig, look up the wholesale price and don't figure any add-ons in the price. The dealer is actually going to give you wholesale less 10% or $2,000 whichever is more. So if your rig comes in at $16,000 wholesale, then you're getting $14,000. It doesn't matter what the figures they give you are, this is what it is worth to them. If the MSRP is $50,000, then they paid $30,000 and maybe transportation. Subtract your trade-in as valued above and you'll know what is happening. If you aren't close, just walk out--tell your salesperson, if they can come to a reasonable price, you'll think about it later and then see what happens.