Have you ever heard about High altitude, high priced vending machines?
Another interesting fact about vending machines in Japan is, that they are so common, that they can be easily found even in mountains and villages. You can see many vending machines even while climbing Mount Fuji, the highest mountain in Japan.
The vending machine drinks usually cost around 1 to 2 dollars. But the higher you climb, the more expensive the drinks become. The price at the summit will be more than double the price at the 5th station. The cost of transporting the items to the summit might be added to the usual price.