Patent laws protect drugs for a certain period of time. Once a drug is discovered, the actual cost of producing it is almost irrelevant. Pharmaceudical companies take out patents on the drugs they discover to get back the investment cost of discovering and testing those drugs. Countries like India don't respect those patents, so people in the United States can (illegally) import these cheap drugs from places like India. Just take a look at the cost (per mg) of generic Proscar vs. patented Propecia here in the US.