New York City’s most expensive apartment listing on the open market is also its weirdest. With an asking price of $85 million, the 15,000-square-foot duplex penthouse at the Atelier — located at 635 W. 42nd St., near less-than-glam 12th Avenue — costs $5,666 per square foot. That’s nearly double the record for the Hell’s Kitchen neighborhood. But what’s really mind-boggling are all the over-the-top extras that come with the place (which, by the way, boasts Hudson River views but no outdoor space).