I think the Black version and possibly in time, the Red version will be the "Readily" available decks, much like the Blue, Red and Black Label Lions. They seem to be following the same purchase model pricing wise as the others did.
The Greenback's look to be the "Rare" version, although who knows what the numbers are, they were just distributed in an unconventional manner, but as of the release of the Black deck, they are no longer listed on the DB site.