Sure, maybe occasionally there are anomalies, with extreme price hikes for specific things in specific places. Right now iPhone X prices seem to be reasonably close everywhere (not-so-great-source: http://www.businessinsider.com/apple-iphone-x-prices-around-...).
I think this doesn't affect my point though, which is mainly that iPhones are just as expensive in generally cheap places.
I don't really trust that chart. Like all tech in Mexico, the iPhone X is 30% more than the US price. I was in the Telcel store in Guadalajara last week and it was 1400 USD as I'd expect.
"Luxuries the same price around the world" is just straight wrong. I don't know how anyone could think that who has lived in various countries, especially for American goods.
For example, no matter where I've lived in the world, it was 25%-50% cheaper to wait until I visited family in Texas to purchase new Levi's.
I think this doesn't affect my point though, which is mainly that iPhones are just as expensive in generally cheap places.