Free T30 Law Degree or Work at a Ratings Agency?

I'm a 20 year old on track to finish college this May. I received a full tuition scholarship at Iowa(3.96 GPA/165 LSAT) for law school, and also have an offer to start working full time at one of the ratings firms on their ABS team in New York (~80k/year). I interned there over the summer and love the work. Long term, I hope to work in Corporate Finance, M&A or capital markets, and was only really interested in going to law school with the intention of going into biglaw in one of those domains. Although I came into College wanting to go to law school and continue down an academic route, I'm not quite so sure anymore.

If anyone has any advice, as well as how common/big a deal the full ride is, it would really help. Also, if anyone could speak to how good/bad an idea it would be to try to get an MBA from an M12/M20 program after a few years of working as a lawyer or lateraling into ib... I would have a law degree at 24 and 27/28 doesn't seem that late to career hop.