Wow, you know I also wondered why the game is priced in yen but instead of complaining I thought for a sec and said to myself, "Hey maybe they live in Japan". Then I took 5 seconds to search for yen usd conversion and saw that a yen is roughly a penny. Then I thought again for a sec and realized that 200 yen is about 2 usd. Then I used Paypal, which actually did the hard part for me and automatically charged me the correct amount after conversion, which was, you might be amused to learn, about the same amount that I figured out in that earlier step.
So anyway, you can use this comment as a template in the future to figure these kinds of things out. I truly believe you can, at some point and after some practice with this example, use critical thinking.