“To see that was like a miracle,” he said of the painting Rompecabezas, one of the works that now hangs as part of Malba’s permanent collection. “You value life, once you recover.”

At the museum’s 15th anniversary celebration in September, art aficionados sipping local Malbecs inspected the declassified Central Intelligence Agency documents on the brutalities of Latin American dictatorships that Chilean artist Voluspa Jarpa gathered and hung from the high ceilings of the museum’s main hall.

New Collection

Young Portenos, as Buenos Aires residents are known, bounced to a DJ on an open-air balcony in a party framed by some of Latin America’s finest artistic gems: Frida Kahlo’s self-portrait with monkey and parrot, Fernando Botero’s voluminous figures in “The Widowers,” and Brazilian Tarsila do Amaral’s “Abaporu,” which she gave as a birthday gift to her husband, the writer Jose Oswald de Souza Andrade.

At his Malba office last month, the billionaire explained how he donated more than 200 pieces of art to create the museum in 2001, and then started a new collection he says is worth tens of millions of dollars. Along the way he set the record price for a piece of Latin American art when he bought a Diego Rivera this year for $16 million, the latest in a string of purchases he admits is a bit like hoarding.

"It’s like an illness," he said of the art buying.

Volatile Economies

The risks of building mega fortunes in Latin America’s most volatile economies aren’t easy to ignore. A realist painting that hangs at the Malba is a reminder for the museum’s visitors of the destitution that Argentina has faced. Painted in 1934, Antonio Berni’s “Manifestacion” portrays the faces of dozens of weary Argentines protesting hunger and unemployment.

Despite his reservations, Costantini does seem bemused by the prospect of reaching the top of the economic pyramid, even if he suspects it may be ephemeral. Asked how it feels to be so rich, he giggles, and after an hour talking about art, kite surfing and how he amassed his wealth, waits for his press adviser to step out of hearing range before reaching out enthusiastically for the hand of his guest.

“So, I’m a billionaire?” he said, grinning widely.