I have never scored a great deal (price wise) at a gun show. I have picked up wonderful revolvers that I wanted or needed, but I always paid full retail. I have had better luck with online auctions, but as you intimated, you are sometimes taking a chance on actual condition. We don't have pawn shops that sell guns up in these parts, so I can't help you there. The forum classifieds are awesome also.
Far and away, my best experiences are at a few local shops that acquire exactly the types of firearms I look for. As 44wheelman correctly stated, a close relationship with the owners of these shops has made all the difference in the world. When something walks in the door of one of my regular shops, I can almost guarantee that I will get the first call about it (usually before they even put it on the floor). I have become friends with these guys and they treat me well. That doesn't mean that I always get below market pricing (I usually do!!!), but I do get the right of first refusal. That's all I can honestly ask for.
I also sometimes go just to hang out when its not too busy. I've been known to bring coffee, or a dozen donuts, or maybe even a pizza for the fellas. Treat people like your friends and they will usually return the favor.
