Since I went left full time employment 3 years ago and started my own web consulting business (see not freelance) I’ve been asked many times how I determine the right time to leave the job and strike out on my own.
For me I saved 3 months worth of money and then when I had so much work I couldn’t do it all, I handed in my notice. I had a supportive wife that just wanted me to work some place I would be happy and she worked full time.
Havard Business Review takes a look at other ways to look at the question. It all boils down to how much you can afford to loose, don’t bet more than that.
If you’re going to play in a game with uncertain outcomes, 1.) don’t pay/bet more than what you can expect as a return, and 2.) don’t pay/bet more than you can afford to lose.