devtrackers.gg
Regional pricing. The devs decided that, since platform publishers wouldn't implement a pricing model that was fair to people in regions whose economy has a lower purchasing power than the 1st world nations the game uses as a baseline, then they would take it into their own hands and make sure that if the price of platinum couldn't be adjusted based on region, then the platinum cost of their store would change to better fit the consumers in those markets.
This is an example of PHXL doing the right and ethical thing with their game and treating their customers with respect.
Meirnon hits the nail on the head here. We do this to accommodate areas where the dollar value is different than NA.