Because it's located in a building with only 11 units, an apartment like this full-floor, pre-war loft doesn't come to market every day. In fact, the last 840 Broadway pad to list got snatched up back in 2008. The 3,000-square-foot three-bedroomcurrently configured as a 2BR with a handsome libraryhas 11-foot-high ceilings and 14 windows... for which it's asking $5,800,000. The maintenance, however, is a relatively low $1,750/month. Exposed brick, custom wooden millwork, and cast-iron columns abound; one of the latter is painted turquoise to match the bedroom decor. Somehow, despite a slightly odd layout because of the floorplan's Flatiron-esque shape, it all works. One more perk: The apartment, located just south of Union Square, straddling the dividing line between the East and Greenwich Villages, is for sale by owner.