I did it the other way round, became a professional student, then PhD student, then postdoc. Now that it's no longer very likely that I'll get tenure - for various reasons that mostly have nothing to do with my scientific performance - I'll have to spend time trying to get rich enough so I don't have to be a professional student any longer. I'll have to fund a company for the first time, while getting close to my 50s, and better earn some money with it.

I don't regret anything, the bottom-line of the story is just that it's hard to know in advance which strategy is better, and even afterwards you can never be sure. That's the problem with the counterfactual reasoning that is the basis of these kind of life decisions.