When freelancing the general rule is assume that will be spending 1/3 of your time with no billable work, and you need to build that into your rate. That leaves

When freelancing the general rule is assume that will be spending 1/3 of your time with no billable work, and you need to build that into your rate. That leaves you with $83,000/year, and you still have to pay for healthcare and vacation time. This rule especially applies to short, 2 day jobs like this. How likely is that you will be able to roll through a string of ~20 hour jobs with no downtime?