I would never pay asking price.
I would have to believe most dealers are going to price high to leave "negotiating" room. In some cases this could be REALLY high so that when the customer negotiates down, they still make a tidy sum, but the customer feels like they won.
I have seen pictures of used rigs on dealers websites with crazy high asking prices (and in some cases you can see from the pics that there is water damage).If you look at the same model for sale on RV Trader and Craigslist you would find them for sale significantly less.