I hear you guys. I've been saying the same thing. Why?
The only thing I can think of is that the guys selling are hoping people will pay whatever price they see at the show because they still think guns shows have the best prices. It's the same thing all businesses do, build up a good reputation, then get lazy or greedy and try to cost on their name. Everyone is guilty of it, but that still doesn't make it right.
You just have to do your homework when/if you go to any shows.