I think its based more on what games they are selling. If they are selling new games im sure they are buying them from Link hidden: Login to view .
Games right now is a flooded market and the profit potential to sell new games even for a big buyer is small profits per sale. If your interested in small profits and can handle mass sales of small profit items. Im sure you have enough to start, Just make sure you stick to hot titles if you can so you can sell them very fast.