It's not every day a townhouse on Fifth Avenue hits the market, especially ones that aren't the Duke Semans mansion. Well, there's a new manor in the house. The Times reports that 973 Fifth Avenue is going on the market for a whopping $49 Million. The Stanford White designed mansion is 15,000 square feet and will be listed under mega-broker Paula Del Nunzio, who is also listing the $90 million mansion (the two places do have some aesthetic similarities.) And talk about a huge profit, the seller bought this place for $600,000 back in 1977. We'll have the listing for you as soon as it pops up.