How much does a hospital chief of staff earn?

depending on location, anywhere from 150k-200k

I disagree. A hospital chief of staff, an elected and temporary position, is often not compensated. Think of it like being a class president. When compensated, it is often at a rate of about $50,000 per year. A chief medical officer (CMO), on the other hand, is a full-time hospital administrative position, and might receive more like $350,000 per year (depends on the size of the organization). Both positions are filled by physicians. At some institutions there is no CMO, and in that case the role may be filled by the chief of staff ex officio. Importantly, however, the chief of staff represents the interests of the hospital's physicians, while the CMO represents the interests of the hospital. These interests sometimes conflict.