It's not only the boat show, went to the last Townsville fishing & Liesure as well as recent home improvements shows up here and have had the same problem.
Unless you are wearing clothing made from $100 notes they won't even t talk to you half of the time. Even had one guy eat his lunch while I tried to get info on having an extension built for our house which could have been a 4 or 5K job.
I have found the same contempt is present in the boat shops here also, unless you are waving the cash they just ignore you.
What ever happened to the old days of "Good morning sir, how may I be of assistance" And thats not that long ago......