When at a dealers table and there are coins out do not put your hands in your pockets unless the dealer is looking at you. I always show my hands palm up before I ever goto my pockets for anything. This will give the dealer a bit of relief as he won't have to worry if your trying to pocket a coin.
Im going to one in Omaha Nebraska on Sunday too! Anyone know how many wheat or IH cents i can walk out with if i bring $200?
Some notes on this topic of skeptical concern: Do not buy or make an offer on a coin without thoroughly examing it with magnification and a point light source. Halogen lights also are efficient in showing things that flourescent or scattered lights will not. Get a copy of the CDN for the issues you are looking to buy. It never hurts to politely offer less than the sticker price. Know all your rights but do not abuse rights by expecting the coin dealer to return your money if you change your mind. In many cases a deal is a deal especially if it is a really bargain deal. If you are unsure on a given coin ask for permission to get an opinion from an expert.