Please read this http://aci.byelarus.com/index.php?p=6#wag-fig. The average wage for a good software developer is close to 1000$ (note that minimum wage is $2.5 per month).
You say he is awesome, that ways I will put his to 2000$. He is consulting for you, so he should make 3X the money as his salary, that comes to 30$ an hour.
The living cost thing is BS. You are confusing between "living cost" and "cost for a good standard of living which everyone in US takes for granted". The former is less, just because more people are very poor, eat once a day and live like hell. I can bet cost for a comparable standard of living to US would be super high.
Just because your developer is OK with living poorly doesn't mean he has to. You can be fair and guide him to a better life.