Okay let me give you a specific case. There is a drug for Hepatitis which is crazy expensive in US at $85K. They are licensing it for $2K in India. Even when you factor for cost of living differences, it is still less expensive in India. The drug companies don't care because they can make their profits in the US while making it cheaper elsewhere.
http://www.nytimes.com/2014/09/16/business/international/mak...