I knew this IT guy who lived in Russia and made $2,000 monthly while the average salary was $300 in his town. He considered moving to US, where he could have easily be making $100-150k yearly, because he was a really good IT specialist with 10 years of experience. But he decided to stay where he is. Why? Let me quote him: “Because where I live, I’m considered rich in my town; but if I move to the USA, I’ll be a regular person”.

I think your friend decided to stay because of his friends, hobbies and habits. Mine just had a fragile ego.