I agree that regional or currency based pricing is not easy and comes with its own problems. But Wikipedia is one of those sites that's freely available and used by people around the world. I wouldn't have thought of the Wikipedia founder starting a venture that charges so much. The 2018-2019 fundraising report by Wikimedia Foundation [1] shows that all the countries in Asia combined contributed less than Australia and New Zealand put together. So he/they must have deep insight into how much money comes from where and the respective ability and willingness of people to donate from different places. They could've as well priced it proportionally with some adjustments on that data.

[1]: https://meta.wikimedia.org/wiki/Fundraising/2018-19_Report