Most decks "need" to deal with the card before killing the opponent, so the card isn't entirely unplayable. Although there are better cards to use (Platinum Angel), I did use Ali in my RecSur deck, and he was really a difficult hurdle for most decks.
Heck, until Long.dec put Balance in their sideboard, plopping down an Ali was game

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It's about $40, mostly because they are rare like hell.