At general antique and collectible shows, Bernie's complaint is valid. At general shows, dealers are knowledgeable in their own specialized areas. When I set up at one of these shows, I make it a point to walk early. For example, I have found chips in the glass lady's booth. She wouldn't know a casino chip from a plastic token; or care. But, to my way of thinking, this complaint ends at a specialized show. Everyone setting up is reasonably knowledgeable about the same things, in this case, chips. There are not going to be any "steals" around to start with. About all the dealers are going to do is shop with 'Wish Lists' from their customers back home. And they're usually doing that for a relatively small profit.
So, no, I don't thinks it's enough to worry about.