One of the distilled spirits classes I teach for I Wish is about cognac. I did one just two nights ago.
In the class, I talk about how cognacs are almost always a blend of spirits of different ages. As prices go up, you get more of the older stuff. A cognac designated XO, for example, must contain no brandy less than six years old, but the fine art of cognac blending is about flavoring the drink with small amounts of older spirits, sometimes much older. The big cognac houses have inventories of barrels going back decades, some as much as 100 years old.
Obviously, the very old brandy is in short supply and used sparingly.
Again as a general rule, the more you spend the more of that older brandy you get. So what do you get for $15,000 a bottle? "A blend of 1,200 ultra-exclusive cognacs aged between 40 and 100 years," according to Luxlist. Remy Martin is the producer. Naturally, no ordinary bottle will do. This one is Baccarat crystal.
Don't look for it at your neighborhood Liquor Barn. London's Harrods Department Store has the exclusive.