Funnily enough, no exile is not the same as outside the game. Before the rules update for Magic 2010 , you could theoretically use cards like Wish to pull cards from outside the game which included the old removed from the game rule
Walk-In Closet // Forgotten Cellar might be the more straightforward playable room card: You just cast the 3-mana green enchantment first, and later when you have a filled graveyard, you get to unlock Forgotten Cellar and profit
Its part of another spell or ability resolving
This spell costs less to cast for each card exiled this way
That, and the mana base, which is so thoroughly whipped to produce a turn 1-2 swinging Francisco that it needs the Magic equivalent to aloe
The card has definitely earned some speculation behind its price tag, so well see how long that lasts