The sellers are both. You may even see someone carrying a rifle slung over his shoulder with a 4 sale tag. (these have to be checked in at the door) It can be hit or miss with when you go. If it's to early,say on a Sunday, some tables may not be open yet. The gun you want most likely will be sold by a dealer.(ffl#1) As far as price, it will probably be the same no matter when you go. You could always try to talk them down in price.
Most of the dealers are about the same in price. Walk around and check first.Then TRY to remember where you saw a better deal. Don't be in a hurry! You WILL be ticked if you buy from the first dealer you come to and find one cheaper later on in the show! (I know) Good luck,enjoy and try not to get a stiff neck.