HELP!

From the stats I've seen, the highest average score from any student body was the low 720s (Yale, was it?). So I would say 720-740 is the "safe" score range to settle on for any school to which you want to apply. If you have time, it certainly wouldn't hurt to redouble your efforts & shoot for a slightly higher score. Since you'll be working at an I-bank, money certainly won't be an issue so don't be afraid to throw down another $250.

That said, 700 isn't bad at all, and certainly not a deal breaker on any application. But its FAR more important to focus on achieving excellence, gaining recognition, and seizing leadership opportunities at your work place, to demonstrate to the adcoms that you have solid potential for rapid career progression and the desire to be a leader.

Bottomline, IF you have time right now and want to retake, I say do it ASAP, because as an investment banker, you'll most likely be so busy that you'll barely have time for personal hygiene, let alone extensive test prep.

Don't worry about the possibility of doing worse. From what I understand, nearly 90% of people who retake the GMAT improve on their score, so your chances are favorable, to say the least.