Well, at this point you won't have a choice but to submit for Regular Decision if you're still asking whether to submit for Early Decision or Regular Decision - since the deadline for ED is tomorrow. Just submit it as early as possible, but resist the temptation to rush -- you're better off putting together a strong application than a rushed one, so long as you get your CBS application in before the end of December (and early January at the very latest).
If you're looking to stay in finance, look at Cornell and Yale as schools that are comparable to NYU in terms of "how hard is it to get in". Other schools to consider are LBS and Oxford -- LBS being about as difficult to get into as Columbia, and Oxford being comparable to NYU.
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