How to determine hourly rate for rack and stack project in Boston?

I'm between jobs and have an opportunity for a 3 day enterprise LAN migration for a total of ~ 24 hours of billable time.
I've only been salaried in the San Francisco Bay Area and am not sure what I should charge as an hourly rate for rack and stack and config with 2 cores and 4 access switches with patch panel links in downtown Boston, MA.