To those saying doctors get paid based on position etc and not race, I'm pretty sure the OP is talking about the cost of training rather than salaries.
Or maybe not, I dunno, because if that were the case then the state is wasting even more money if some doctors can't find jobs according to some sources posted here. Which would actually make them more expensive alternatives.
Just re-read it, the OP said cheap labour - so yeah, that argument is flawed.