There is one line for someone who wants to use "a personal buyer" at the National.
The "personal buyer" is one person who has real time access to a message board where a group of dealers are located (here for instance).
The dealers would respond within a few minutes if they had the card this specific buyer was looking for. Set the minimum value card to be searched at around $250. If someone is serious enough, they will wait in line for this service and pay a small finders fee perhaps. Connects many dealers instantly with serious wants lists.
I'll be anyone's partner who wants to start this business with me.