Earlier quoted context omitted.
Good point, I didn't think about the value of being able to do other activities. Hard to quantify with a monetary value though!
Actually it's not difficult. Calculate your hourly wage (salary + benefits)/hours_worked, and value all of your time as such. It will help you a lot to avoid wasting time doing stuff you don't like that you can pay people to do for you at a lower cost to you.
I do pay to have a number of things done for me on a regular basis that I either don't like to do or don't consistently have the time to do (like getting my lawn cut), but it's more about how much I'm willing to pay for the service as opposed to how the $/hour compares to what I earn.