Interesting idea. So, yes, different countries has a different status of economic sytem. And USD prices can be extremely high. I even say that it should be at least half ot the world, if not even more. So USD is for USA direction. And some more, some more countries, people. But, this is a USA dev, so they do it for USA first. And yes you can be a guest here. A guest. And play the game. USD prices and so on. This is the way i see it.
From other hand, you know, i have read article. And it tells, that if you are not from USA, you can be enough about 200-300 USD for minimum or normal, or have 500USD or more to be very cool about earning. So US residents i heard, they need 3000USD per mounth to have a minimum.
So in result, it has some different points.