Commodity like other resources will always follow the market price.  The fact that India has higher prices it is due to ineffeciency in its system.  

Value added products and services on the other hand are not equal.  Going to a Dentist in India is not the same as going to one in the US.  Eating at a restaurant in India is not the same as in the US.   Those that want to experience US quality in India hpay higher prices than in the US.

PPP is flawed because it compares apples to oranges. It failed to take Standard of Living, efficiency, productivity into its equation.