Your description of hoarding is accurate and I feel can only be applied to the LE's currently flying out of the casinos like flies to dog poop!

As for scarce or rare, first off they are considered scarce or rare because there are a VERY limited amount known to exist, probably less that 20 for arguments sake. If someone makes a "find" of say 100 or more and does not tell anyone and continues to sell as if they were STILL scarce or rare, then that's called DECEPTION, not hoarding.

There is a HUGE difference in these two scenarios that I've just presented to you.