[ashark]

One of the key insights about his situation, I think, is that you can live on his under-30K budget and not feel super poor, if you don't have regular 9-5 job with a fixed location, if you don't need to worry much about good schools (can homeschool—these two things combine to mean you can choose inexpensive housing with fewer other trade-offs, which makes it easier to have a paid-off house), and if you already have a lot of money and in-demand skills so you can reasonably have much lower insurance spending generally, and especially health insurance. The overwhelming bulk of his budget savings comes from already having lots of money and from having plenty of time to DIY stuff others might pay for. The rest is useful but relatively marginal.

His blog's good for reinforcing that you can spend less money when you already have money, so it's heartening in that it tells you your target income for retirement can be much lower than the income you need pre-retirement. It's not especially helpful for getting there.