It's not a complaint....it's poor marketing. Flood the market with gun shows every 2-3 weeks and you flood the market with supply (gun shows), and demand (attendance) goes down.
I stopped going to the Mesa gun shows because I kept seeing the same vendors in the same spots, with the same overpriced guns on their tables. I had more luck finding interesting guns for sale by just setting up a folding chair out front, and asking people what they were selling.
Every vendor charges sales tax, and most of the time I can find the same item online for cheaper, including the transfer fee. My big hobby at gun shows is picking one or two guns, and seeing the huge range of prices vendors are charging. Last show I went to it was the Sig P365XL; I saw prices from $539 up to $640 (the two vendors were 50 feet apart!)
The only thing I end up buying any more is beef jerky.
The SAR show is really the only interesting show that happens, and even that is becoming repetitive.