I have sold a couple of campers but no where near the NADA value.
My bottom line is to do a nation wide search for like campers and get a feel for the water on the real pricing. Discount the outrageously priced ones and try to sort out the ones that are close to the bottom line.
I am an out the door price guy. Last car we bought I did not even fiddle with pricing/cooking the books. i knew what I wanted and it was out the door right up front. Took about 30 minutes to get to the bottom line.
Just remember, as I foggily recall for some reason, that Toby Kieth once proclaimed, if you cannot afford to walk you will never get the price to your satisfaction or "a good deal".