Sotheby's sells the Upper East Side

How about a penthouse triplex? $42,000,000. Right on 5th Avenue.

Stunning Candela penthouse triplex, 12, 13,14th floors. Special features include extraordinary Park views, a private elevator to all floors, 4 exposures, dramatic irrigated terrace, magnificent paneling, 5 fireplaces with beautiful carved mantels, single pane windows and hand carved moldings. There is on the reception floor a magnificent entrance foyer with inset marble floor and carved double doors to the living room and dining room both with 11’ ceilings. A spacious chef’s kitchen and staff Room completes this floor. A staircase leads to the 13th floor library also with a magnificent fireplace and spectacular Park views. A butler’s pantry and powder room plus 3 master’s suites comprise this floor.

The 14th floor hosts the master suite, with large walk-in closets and a separate sitting room with a fireplace. Both rooms have single pane windows and sliding glass doors to a magnificent terrace with dazzling Central Park views.

You couldn't get me to live in an aerie - I'm afraid of heights (although I love riding in airplanes).

So for me, a townhouse would be ideal. How about this one ("Spectacular Limestone Mansion")? $50,000,000.

This grand and elegant neo-Italian Renaissance mansion is exceptionally wide (45’) and one of the largest and most important townhouses in New York. Commissioned in 1922 by Julius Forstmann, a prominent German merchant, the house was designed by C.P.H. Gilbert, the renowned architect who created majestic mansions for the leading families of the city. Behind a stately and distinguished limestone façade are five floors with an additional garden level and a full sub-basement comprising a total of approximately 21,000 +/- sq ft. The dramatic entrance foyer leads to a magnificent reception hall and grand-scaled rooms which feature many superb original details, including a spectacular sweeping marble staircase, an enormous skylight, marble fireplace surrounds, hand-carved moldings, and soaring high ceilings. This extraordinary townhouse offers the rare opportunity to own a Manhattan landmark with the versatility of luxury residential or trophy commercial use.

Wow, a double-wide! Love the history, too.