Saint Helena produces what is said to be the most expensive <answer>coffee</answer> in the world. It also produces and exports Tungi Spirit, made from the fruit of the prickly or cactus pears, Opuntia ficus-indica ("Tungi" is the local St Helenian name for the plant). Ascension Island, Tristan da Cunha and Saint Helena all issue their own postage stamps which provide a significant income.
What does Saint Helena have the most expensive of?
coffee