1. Lack of inventory 2. The market is starting to upswing 3. Coin prices for various series are increasing, possibly due to lack of inventory. I was looking at Bust Halves which my wife and I starting to have a fondness for, and for nice XF AU grade specimens they are going around 100 to 150 above gray sheet. Years ago, I would be purchasing these near or just above gray sheet any of you experiencing this?