Undeniably, Petrus can be excellent. But is it worth $500 and up per bottle? In a sense, the question is irrelevant. Even if it were $3,000, Petrus would be a sellout. There are two reasons for this: First, only about 3,000 cases are made annually; second, the more famous it gets, the more people want to taste it.

It hasn't always been so. One of its early British champions was wine merchant John Armit. "I started it off," he noted, "but Petrus soon developed a momentum of its own." The enthusiasm of influential American wine writer Robert Parker helped to create a demand in the U.S. So did the charm of Petrus director Christian Moueix, a regular visitor to America. And so, to be fair, did the wine itself, especially the voluptuous 1982 vintage. Suddenly, everyone wanted Petrus, no matter what it cost.