Some of the passengers prefer comfort first in air travel, which is the reason they pick the first-class cabin with aware that the price is higher than the other classes in Japan Airlines. The cost of the first class is flexible with some factors like route, date, time, departure location and some other reasons not clearly disclosed by the airlines. But the general price of Japan Airlines First Class starts around $5,800, and it's not fixed; it gets higher if the flyer books the flight for an international route. For more information, visit the Japan Airlines official website or read the mentioned blog link of the FaresFirstClass.