The article says these tests can be "at a cost that is as much as 80 percent less than going through a doctor", what can explain that kind of discrepancy beside

The article says these tests can be "at a cost that is as much as 80 percent less than going through a doctor", what can explain that kind of discrepancy besides rampant corruption in the "official" medical lab work market? The difference is that one is paid for by a health insurance company, and the other is paid for out of pocket by the consumer. The second group is much more price sensitive.