However, from a bootstrapping perspective, I think it is useful to look at the value of your time in a different way. If you are thinking about leaving a job that pays $100K at big company X to bootstrap something, you might think of your opportunity cost as $100K. But a lot of that $100K will go to taxes, so when you quit your job you really only loose $60K. What's more, you might spend more on living expenses with your big company job (vacations, etc), that you would give up while bootstrapping but not really miss. So, maybe you are really giving up something like $30K/year in true lost value.
I quit my big company job about 9 years ago to bootstrap a very small company. It has worked out well, and proved quite profitable by whatever measure of opportunity cost you'd like to use. But because when I quit, my taxes went to zero and my expenses went way down, I found that the actual cost to me of forgoing income for a period was much lower than I had imagined.