Only fifteen percent of the coffee grown in Jamaica is authentic Blue Mountain Coffee, and the coffee from the Wallenford Estate is considered to be the "cream of the crop" of ALL of the Blue Mountain Coffees. This coffee is imported from Jamaica in wooden barrels and certified to be 100% Jamaica Blue Mountain Coffee by the Jamaican Coffee Board.
Why is it so expensive? Simple economics really, it's rare. There is so little of it, and so much demand for it. Most of the JBM coffees are sold to Japan, where it commands a VERY high price, which leaves even less for us here in the States.
But rarity is not everything, this is still an exquisite coffee! Rich, deep, sweet, and roundly full-bodied. Delicious. Hence the tremendous global demand.