Chancellor of the Annex has been hot and cold in degenerate decks in Legacy basically since it has been printed, though it has never really been the stock option for a convincingly powerful archetype. As of late though, Rakdos Reanimator has been making waves in Legacy.
This deck is committed hard to just going off on turn one or two instead of using blue cards for consistency. As such, Chancellor of the Annex takes the place of Force of Will while also being a reasonable creature to reanimate. This deck doesn't offer a lot of play, but it is pretty good at ending the game very quickly.
As of this writing, foil Chancellors have basically disappeared from the internet, and cheap copies of non-foils are being swept up. The card was only a buck or two, and is likely to be at least $5-6 before too long, and could ever settle higher. Scooping up some cheap copies or digging up a foil to sell into the hype would be a good move.