If it weren't for the fact that I'm buying games under retail on the regular, meaning that I'm constantly spending money, I'd consider going just on the hopes of finding a deal, but from my experience, resellers at these cons always wants up and over retail. But that's just my experience. It doesn't matter if it's video games, figures, comics, or shirts and stuff... it's always more expensive at cons than on ebay. When my wife and I would go to cons, we would just use it as a method of finding out about stuff for us to go buy online... at least in terms of dealers areas.
In MY area, when we have cons, a few of the local game stores will set up booths and they will take their store products, mark up the prices, and bring them to the con. So already high prices get marked higher.