Its PPPee comparing to prices in US; and consumption pattern ignored (eg: CPUs aren't cheaper in china)
Bharat has a popn close to 1.4 billion, norminal GDP = $2.9 trilion, 'PPPe-ed' to $11 trillion
https://www.businessinsider.com/haircut-cost-around-us-map-2014-3
According to the link above: 'the average woman's haircut in the U.S. costs $44, and the average men's trim costs $28"
Lets say the average is $36 and the average persons have say 8 to 9 cuts/year, so the average person spent $300 on hair cut, so existentially 1.4 billion people, rich or poor, create GDP worth > $400 billion OR that $400 billion vaporise if they all have the hair cut by their family members.
(Of course, economists can also tell you how $400 billion can spin-off other econ activities like helping advertising, construction of barber shops... ; if I remember right at a multiplier factor of 1.4, there's a term for it which I forgot) .
Another BS is BicMac index: The average hindus siimply can't afford regular meals at McDonald and the BicMac in Bharat are chicken sandwiches which are cheaper than beef ones.