Kopi is Coffee in Indonesian language, and Luwak is a kind of civet which is considered as pest among Indonesian farmer. Kopi luwak itself refers to coffee which produced by luwak, which only eat the finest, the ripest, the reddest coffee cherries available on the plantations. The excrete of Luwak's digestion process is what we call Kopi Luwak. What? The most expensive coffee is coming from animal's ass hole? Haha,.. you are right. The enzymes in the animals' stomachs add something unique to the coffee's flavor through fermentation.
100 grams of Kopi Luwak cost around US$50, but some cafeshop already offer this kind of coffee for 5 dollars each cup. It's small amount of money comparing hard effort of farmers who have to collect animal shit all day long.