How to get cheap in-app purchases?

A lot of games have packs that you can purchase and they are very expensive, especially for things like Game of War or Mobile Strike. On Android, if you change your local settings to a different country in your Google Wallet as well, for example: Mexico, you can buy things slightly cheaper than, say, in the U.S. Does anyone know where in the world is the cheapest to buy in-app purchases from? I've seen people try Brazil, Russia, etc. --- A lot of people get things for cheaper. But when their gold reaches 50k, the pack price changes and for some reason it no longer works, so they can't get cheaper packs. I was wondering if anyone knows a way around this?