This is one of the reasons the young and the nerdy tend to have an advantage in starting startups. They have inexpensive tastes. So they feel prosperous on an income that would make someone older and more conventional feel poor.
edit: Of course, right now the "whole time value of money" is basically negative. ;-)
If I value my time differently depending on what I'm working on -- if the startup is lots more fun -- then it's an easy choice.