I sell in order of replies. To a point. If you ask for more pictures I'll send them. But that doesn't hold the game. If several people ask for pics then the first one saying they want it gets it. If you say you want to come look at the game in the next few days. I will will hold it until that day. If you show up and try to lowball, your out the door. I'll move to the next person inline wanting it.
The other issues I have seen with some sellers is: They offer a game at a price. You say you want it and can pickup that weekend. Seller says ok but then gets another offer for more money and sell to next guy. This is something I would never do.
I sold several pins and vids where other people contacted me offering more to sell to them. Turned them all down. One was even a grand more.
I have bought and sold many pins and a lot more vids since I started collecting in the late 90's. One thing I learned is your WORD and reputation should be a top concern.