For a master's in finance, they will definitely want to see a strong quant score at those schools. If you think you can easily bump up the Quant to a Q48+ while atleast keeping the verbal the same, this should push you over 700. That score will be looked upon more favorably, and at 680 you havn't quite reached that hump where you've received a "very strong" score.
But you will also have to consider how much time you have before applying, and if retaking will take away from other parts of your application. Make sure you use your remaining time wisely so you get your best return on investment of time. Good luck!
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