Be very careful! If you buy something and there's a problem, the guy you bought it from might not be around for you to run back to. I've bought a lot of accessories - holsters, cleaning equipment, and stuff - at gunshows, but only one (new) gun.
That gun turned out to have a defective part. Fortunately it was an Arsenal, Inc. product; and, the factory took care of it for me at no charge. (Of course they, also, had my new carbine for almost 8 weeks; but, they finally returned it in perfect working order and condition!)
I really liked that gun, and couldn't find it anywhere in my area; so, when I saw it at the show, I immediately bought it. (Paid more than I should have, too; but, as things turned out, it's my favorite toy; so, it doesn't matter!)
Personally, I prefer to use the shows for ammo and accessories; and, this philosophy has saved me from buying some of the crap my friends have, sometimes, come home with. My own attitude has long been that if you show me ten gun dealers, I'll show you three honest men.