Large or Small, Same Price

Maybe you've heard the story about the American who goes to Japan and sees a vending machine selling Cokes in a large size and a small size, both for the same price. He buys the larger one - of course - because it's better value for money. His Japanese friend buys the smaller one. The American is incredulous. "Don't you feel like you're wasting money when you could get more soda for the same price?" he asks. His friend is surprised at the question. "But it's a waste of soda to buy more than I want to drink." This is supposed to illustrate something about the difference between the American and Japanese value system. I'd always considered it an urban legend, because usually, small drinks in vending machines cost about 30 yen less than large ones and I'd never seen large and small ones being sold for the same price. Until now.

Same product, same machine, same price, whether you choose 500 millilitres or 310. It's water, not soda (I noticed that the Pocari Sweat sports drink, which also came in a large and a small version in this machine, was 150 yen for the large and 120 for the small size). But maybe there's something to that story, after all... Now I just have to figure out what point it's supposed to be making.