I disagree with the common Med school statement, "If I wanted to make money, I would have gone into business or law". First of all, the way BIGLAW works these days, you'll need to work 65-70 hours a week in order to make more than your reasonably successful doctors. There's the pressure to attain billable hours requirements, the need to fit into the culture of a corporate law firm, and the fact that you need to be willing to work all night even if you have a family if there's a big merger and you're responsible for the paper work. This doesn't change when you make partner, it only gets worse (except for the money, of course).
In some cases business has better hours (in some cases it doesn't) but it's also a tremendously risky career regardless of what business school you go to. B-school gets you a job making 100K+, but whether you have that job in a couple years depends on your talent, whether your talent fits into the company, whether you're in the right place at the right time (i.e. luck), etc. It's not a guaranteed living the way an MD is, there are a lot of smart people who fail at it.
In contrast, MDs make a salary they can live on during their residency and then are guaranteed either a comfortable living or a decadent living for the rest of their life (depending on specialty, region, etc.)