It's true that chips are "flying" all over the place on the convention floor, between dealers & customers; buying, selling & trading. The only thing to caution a first-timer against, from an ettiquite & common sense perspective, if not to undermine a transaction in process between a dealer and customer by jumping in and offering the same item for less $ (or in trade). The dealer has paid for the "real estate" in the immediate vicinity of his table, and has exclusivity while the transaction is in process. (Now, if the customer declines the purchase and moves on, then a trade or sale could be proposed. Just a sort of "no poaching" courtesy we all should expect of each other, whether dealers or not.

(Jim, I didn't think your post was condoning such "poaching" activity. I'm just commenting in general for those rookies out there.)