Regional pricing isn't new, nor introduced by Amazon - international companies have worked this way for ages: maximise profit by doing different pricing in different markets for the same product.

Or varying the product so that it is not exactly the same: https://www.euractiv.com/section/health-consumers/news/lower...

A prime example of regional pricing was, of course, the region code system for DVD movies. And the modern incarnation of this is regional pricing for streaming services such as Netflix, along with trying to stop people from accessing services via VPNs.