Rupert Murdoch may one day move in to his $44 million apartment at 834 Fifth Avenue, and when he does, it will no longer be the city's most expensive co-op. That honor goes to a penthouse duplex at 1060 Fifth Avenue, which the Observer's Max Abelson reports will sell for $46 million. Except, here's the thing: even though the seller?rich guy ex-wife Georgia Shreve?uses the apartment like a duplex (using the building's stairs and elevator to go back and forth), it's actually two separate apartments, and the co-op board has already turned down plans to combine the units once. So hedge-funder Scott Bommer is technically paying $46 million for two apartments, and he hopes to spend a pretty penny more to combine them, if he can even get permission. Oh, those on-top-of-the-world hedge fund stars!