Career-wise it would probably be a one-way trip. Investment banks are notoriously narrow-minded in their hiring process, and I doubt I'd be able to break back in once I left the industry for a year or two.
I also have three kids under 6 who I like to spend time with, including a newborn, and I'm geographically limited to this area because my wife owns a business that has deep local roots. We have 3-4 good schools within an hour, but if I don't get into their programs I'm kind of out of luck.
The grad schools nearby have minimum undergraduate GPA requirements of 3.0, and I ended up with a 2.9. I assume they'd waive the requirement if I had great grades in a post-bac science program and a great GRE, along with my 4.0 from business school, but it's unnerving to have so much riding on the whims of an admissions department. Plus even if I did manage to get in, I worry about how hard it would be to get a post-doc position as a 50 year old.
I realize it sounds like I'm just making excuses, and maybe I am. I have a comfortable, happy life, and there's a level of irreducible risk on this alternate path. As of now I've decided I'll start taking some science classes in the evenings at the local university next year, once my baby is a little older, and see where that takes me.