Because it's not posted publicly. According to @EA_Blueberry we don't buy and sell to real people. We buy and sell to bots and the only real role we have is setting the price based on what we post an item for. I think it's terrible myself. Takes the human element completely out of the equation. There has to be a better way to stop the cheaters. All these cheaters and hackers have really messed this game up for the rest of us.