And a doctor in Africa earns $50 per month.
I have no idea what a doctor in Africa earns. However, whatever he earns will be governed by a number of factors. One of which is "money available to pay him". Another being "market forces". Another being "cost of living".
Funnily enough, those factors drive my salary, your salary, Bronco's salary, Bronco's brother's salary .... you get the idea yet?