I used to work selling and maintaining instruments primarily to physician's offices. They were all 50k+. It depends on the tests being run, and what type of insurances the patients have. If they have good insurance that doesn't require the blood sent out to Quest or other mega lab company, they can make decent money on specialty chemistry tests.
And yes, these doctors would order absolutely everything they can bill for as it was going in their pocket. Homocystine, and Vitamin D are 2 high reimbursement tests they liked a lot.
However as I always said about Theranos they have no technology that could possibly work for a wide variety of analytes, and this is already a very competitive market in both equipment and labs. They still don't have a chance. I have no idea how people were so fooled by this. A 40+ billion dollar long existing industry that relies on heavily regulated hard science is not going to be disrupted by a college dropout.