[jltsiren]

You can do many kinds of research with minimal overhead, as long as everyone is self-employed and your funding comes with minimal restrictions and reporting requirements.

I did that for a couple of years as a CS postdoc on a private grant. I believe my overhead rate was 15-20%, which was mostly health and other insurances. To reach that, I did accounting and taxes on my own. I also had a loose affiliation with a university, so I didn't have to pay for office space or computing.

If you start using paid services, hire employees, and accept more restrictive grants, your overhead rate can easily climb above 50%.