It's at the Raritan Center Expo hall in Edison. It may be worth it but I bet it won't be local dealers.
I know 2 people who went to a Thermospa show in Fort Washington PA about 2 years ago and they had blems and seconds. They both picked up their tubs pretty cheap (3000 and 5000 I think). They went knowing it and are happy with their tubs.
Give it a shot if it doesn't cost you anything to get in. But from what I've read on this board, it might be mostly one company luring people in to buy.