Also is dependent on the state where you will practice and incorporate. And what private insurance is available for you as far as health, and what the malpractice insurance
rates for your area. Disability insurance, etc.
Workman's Comp if you want to be covered under that. As a single employee of the corp, you can opt out of that, but that is another that you take.
And when you figure in the benefits that the job would provide, such as paid vacation for x-number of weeks, usually about one month; you need to calculate that in as well.
But the biggest issue will be the state that you will be practising in.