Sorry if this has been asked, but what is the deal with the rarity rating on the coin facts from PCGS?
I was looking at
Barber halves on
ebay and a seller had rarity rating on the 2x2s. There were not the traditional rarity ratings. I figured out, after a while, it was the ones listed on PCGS Coin Facts. Why he put them down, I don't really know. I guess to make his (mostly low quality

) coins seem rare.
For example on PCGS coin facts, they list a 1912-S Barber Half as having less than 3500 existing in all grades. Is this even possible? There was a mintage of over a million. 99.6 % of them disappeared? Did they all get melted for the silver?
Are there that few collectors of
Barber halves around? Because I picked up a 1912 S in the local coin shop for $12-$15. It does not seem such a rare coin would be so low priced (not that I am complaining

). And there are over 200 on
ebay right now!
I can see some of their figures being correct from something like the
Shield nickels, which is a much older series and has many coin with lower mintage. However to be the
Barber halves figures seem off.
Any thoughts on their rarity rating in general or with the
Barber halves specifically?