That's common, even with a dealer that is at a certain show.
We had a 2011 Aerolite HTT that we paid 15.4K for in real numbers in Sept of 2010 from a local dealer. The following spring after the Pittsburgh RV show I ran into a couple who had the same model trailer from the same local dealer except they had purchased at the RV show in Jan. He told me how great of a deal they received because of the special RV show price which was 16.9K. I ruined his weekend, he didn't believe me until I showed him my paperwork I had in the trailer.
I love going to RV shows and playing with the salesmen to see what kinds of BS I can get them to tell me. If you want to have fun with them.... find a 40' 5er and ask the salesman if you can tow it with a 1/2 ton truck with a v6