It's no Graceland, but 151 East 72nd Street will have to do for Mr. Sillerman.

After his $50 million golf venture on the Caribbean island of Anguilla went spectacularly awry, Robert F.X. Sillerman told the New York Post, "I think I have shown conclusively I’m not knowledgeable enough about the real estate business."

Poor judgment in the West Indies aside, we're betting that the music industry Renaissance man—Mr. Sillerman's business interests range from the concert promoting titan that became Live Nation to Elvis's old Graceland estate—will do a lot better with his latest purchase: a $12 million limestone townhouse on the Upper East Side.

The five-story, 18.5-foot-wide home was sold by HBO CEO Richard Plepler, who was not easily parted with the townhouse. After buying 151 East 72nd Street for almost $8.2 million in 2002, he got greedier than a Valyrian slave trader and tried to double his money by asking $18.5 million in 2008. While he may have had some takers a year earlier, Lehman Brothers declared bankruptcy not a week later, prompting his broker, Jaar-Mel Sloane of Sloane Square, to pull the listing a short time after.

Three and a half years later, Mr. Plepler and his broker tried again, listing the unit for $16.5 million. With no takers half a year later, they finally arrived at a more reasonable asking price: $13 million.

Two months later, a deal was struck—a deal that we now know was for $12 million, according to city records.

The house itself is a bit of an odd duck. Despite its five levels, it only has three bedrooms, though they're all labeled "master bedroom" on the floor plan. What appears to be the real master is two stories tall, with half of the second being open to the first. And while the house doesn't have a proper backyard, it does have an addition that provides for a sky-lit dining room and terrace above.

To enter the house, Mr. Sillerman will have to descend half a level below-grade—we'll call it a limestone take on the New York City club experience.

Mr. Sillerman's neighbors will be pleased to know, though, that despite his February acquisition of Beatport, the online electronic dance music megastore, there will be no grimy dubstep or booming bass emanating from 151 East 72nd Street: his own tastes lean towards Bob Dylan and Paul Simon, according to The New York Times.

What's $11 million to a billionaire?

There has been a lot of talk about billionaires buying up Extell’s One57 tower of late, but the old quarters of New York still have their draw. Take the fortuitously named Ron Baron. The founder of Baron Capital Group, he has made a very lucrative career of investing other people's money. He has created a $1.5 billion fortune for himself along the way, according to the magazine of the same name, where he ranks as No. 311 on the Forbes 400 list out last week.

Even more than investing other people’s money, though, Mr. Baron especially likes to invest his own, with a particular fancy for real estate.

Mr. Baron and his wife Judy have purchased a five-bedroom, 5.5-bath co-op at 1000 Park Avenue for $11 million, according to city records, buying through the DRB 1998 Trust, of which they are trustees. But given that the Barons already have a duplex Park Avenue spread, it seems unlikely the apartment has been purchased for personal use.

The Barons own multiple homes, of course, including one in Vail and another in the Hamptons, purchased for $103 million in 2007 (the most ever paid for a residential property at that time), but two Park Avenue co-ops seems a bit like overkill. And if the Barons wanted to move we guess they'd probably pick a pricier pad, say something along the lines of the new $95 million listing in the Sherry-Netherland.

Still, as the prewar pad is in a co-op building, it must be for somewhat personal, most likely familial, use. And why not pass a passion for real estate on? After all, Mr. Baron's real estate fixations started when he was quite young, as a child in Asbury Park, N.J. As he once told Forbes: "My family had a $20,000 house. My friend's family had a $50,000 house. I wanted to have a house like my friend's."

The Barons bought the co-op from fellow financial bigwig Robert Cochran, the former CEO and chair of Financial Security Assurance Holding and his wife Suzanne. They had been asking $12.9 million when they listed the co-op last November with Sloane Square broker Jaar-Mel Sloane. (The ask dropped to $11.5 million in March).

And, while the apartment may be a lesser trophy compared to some of the choice residences on the market at the moment, it's still perfectly lovely. On the 12th-floor, the 12-room co-op features a library (wood paneled) and living room (wood burning fireplace) and not one but five master bedrooms. Is that even possible? Can there be more than one master? Or, like penthouses, are master bedrooms now proliferating? Because what master of the universe wouldn't want more than one?