It's still early yet. I heard the Red Artifice was going for about $30 when it first hit the aftermarket, but that changed soon after. It wouldn't surprise me at all to see Black Crowns go up - I'd guess between $50 and $100. (Don't know EXACTLY where, but in that range.)
That's the thing about rare decks: they never, ever get LESS rare...
Are you sure they will go between $50 and $100, because, that itself it just outrageous! Although, the entire deck does remind me of the Centurions, simple box, contrasting color, limited supply, crazy after-market prices, ect.
Well, the $109 for 4 decks turn out to be like $27 per deck, Sabacc meants $50-$100 EACH - that's crazy to me.