I'm not voting as I own the hat in the third link, but my trade has only been active for a few days, so it doesn't really qualify as good evidence for anything. And the first link's trade is closed to inactivity. All the rest of the trades are 5 days, 1 week, and 3 weeks old. Unusual selling takes a significant time for good offers to come in, and with the possible exception of the 3 week old one none of these trades have been on long enough to get any real data.