One of the things you don't see much about is US doctors who practice in Mexico.
They continue to live in the US and commute across the border to run their practice in Mexico. There they see mainly US patients who cross the border to visit them. http://www.thedailybeast.com/newsweek/2 ... rcing.html
One of the big factors is malpractice insurance. In some specialties, in some states like California, the cost of malpractice insurance per patient visit is $15-25.
That is before rent, lights, employee salaries, taxes and so on. Also before what the Dr has left over to take home to live on.