How do all these DOs in primary care make a living?

I'm talking about the DOs with student loans above 300k (most of them) and primary care salaries well under $170k (most of them). At my school, my total student loans will be $400,000, which by the end of residency, has compounded to $650,000. This means that, with a $150k salary (realistically), ill owe $60k/year in taxes and 65k in student loans, leaving $25k, which doesn't take into account malpractice insurance (which often exceeds $25k). These numbers aren't adding up. It seems to me... How do all these DOs in primary care make a living?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums