[Kaizyn]

This really comes down to two things: 1) How much income do you need to cover your yearly living expenses? and 2) How easy would it be for you to go back to earning 300K/year if you were to take the time off for your startup?

I'm sure you've seen all of the figures about compound interest. Were you to invest even $30,000/year for the next 10 years, you could easily retire a multi-millionaire without hardly noticing the reduction in your standard of living.

Retirement aside, I would suggest that you pay off all of the bills you possibly can first. That way, you won't have the same sort of pressure on you to produce from your startup you otherwise would face. Good luck with this venture!