Gun shows are OK. I tend to buy off FFL dealers though when I'm in one. I've got some really good deals and with a dealer you get the background check and all..less likely to be a stolen gun or anything. The shows I go to are a bunch of dealers in the stater. Bud from Buds Gun Shop has had a booth at many. I'm sure many of y'all trust em being you have bought guns sight unseen from his inventory.
As long as you go in informed and look at what you are wanting to buy pretty well a used gun can be a good purchase. Like I said though. I like the FFL dealers at the shows. These people have a store you can go to if you had any problem. They are not as likely to sell crap and run like some private seller. They do this for a living. Most dealers that go to the shows bring with them things they have had in inventory a while and want to move. Maybe got a deal on a bunch of one kind and wanna sell off a bunch. I see a lot of the Smith M&P's at the shows here. Ptretty nice deals if you like the pistols. Things like that and Duty tested Sigs I see a lot. and of course overpriced collector pieces or the ones that are going to be around not to long because of some strife someplace or a new ban..lol
I don't like buying used off a private seller unless it's someone I know...and pretty well.