I'd be quite surprised if "Memphis"'s minimum weekly operating costs were only $500K -- with that size cast, the running crew likely required to manipulate the physical production, dress the cast, the theatre deal for the Shubert, and especially the amount of advertising they're been doing, I have to believe it's at least $550K and perhaps even closer to $600K.
Either way, even if you're numbers were spot-on, it's unlikely that the show has returned more than 10% of its capitalization and I daresay, even if it wins the Tony, I think there's still a better than average chance it could be gone by Labor Day. I'm not hoping for that at all, but such are the harsh realities.
"No matter how much you want the part, never let 'em see you sweat." -- Old Dry Idea commercial