It's hard to pin that down exactly, but let me put in these terms... the dollar number I've long had in mind as "I could quit working, live on savings/interest,

It's hard to pin that down exactly, but let me put in these terms... the dollar number I've long had in mind as "I could quit working, live on savings/interest, and do more or less whatever I want with the rest of my life, without living a lavish lifestyle" is $14 million. If I, say, sold a company for enough to where I walked away with that much (after taxes, for the sake of argument) I'd buy a house (not a fancy house either), a car or two, a bass boat, and the rest would go in various mostly long-term investments. I think I'd be pretty settled at that point.