We have all been taught to buy the coin not the holder. It seems that may be over. Heritage has a big auction going on today on holders. Just this morning I saw an add for the new Greysheet holder by NGC. Stacks Bowers had it's own label. Maybe we were mislead. I once was think of a small collection of the older holder styles of the big three, NGC, PCGS, and ANACS. Now it is "All the rage". 

I guess, but I want to collect coins, not holders! LOL

Of all the differing "man-made rarities" I believe that the many different labels, holders, or terms such as "First Day or Issue", "FirstStrike", "Early Releases" or "First Releases" which added to labels are the worst type. If a coin is struck low mintage to make a man-made rarity, it is always a low mintage. But if a coin has A. A unique colored special-edition holder that is super rare and it drives up a coin's value B. A label such as the Greysheet label mentioned by @Longstrider that is rare and drives up a coin's value, or C. A term that literally should have no bearing on a coin's value such as the terms I mentioned before which cause people to pay morejust because the label says: "Early Releases". Examples for A are the NGC holders that glow in the dark, examples for B are the "black labels" you see on slabbed ASEs, examples for C are the terms I mentioned above. Interesting fact, "First Releases and "Early Releases" mean basically the same thing, so they are useless. But why do collectors say to "buy the coin not the holder"? It is because holders are not what the hobby is about. It is about coins. If you want to collect rare labels and holders, then please do. But true numismatists know that it is not about the holder, it is about coins.

Agreed.

The early ANACS photogrades would be nice to collect. Tough to find and priced accordingly.