It's very easy to criticise when you have no idea what's involved. As a show organiser, I can assure you it's not about "trying to spin money".
The local industry here needed to be stimulated as a way of finding new audiences and exposing them to quality hi-fi and sound. To organise this one show per year, my wife and I work full time for over 5 months on it, and there are ridiculous amounts of costs involved. From hiring registration desks, thousands of dollars of printing, marketing (extensive), insurances, lanyards, wrist bands, security, in-show banners and signs, then the biggest one - the venue costs.
We also have a large spaces that is $16K AUD to exhibit in for the weekend. It's all about taking your costs, putting a margin on to justify the work (because I imagine like you, we have bills to pay and would like to be paid for what we do).
My point is, perhaps you shouldn't just make the assumption that it's just a money spinning exercise. You clearly do not understand the associated costs and work involved in running a successful show.