Well it depends on the rest of your profile and the schools you are targeting. But remember, even the top schools in the world only have average GMAT's of 720 or 730 so your 710 will not keep you out of any school in the world. But a 740-760 might slightly improve your chances. Since you have so much time before applying, it might be something to consider. BUt at the same time, you might be better off spending your time and resources on building other areas of your application. You can begin new extracurriculars, and try to get leadership positions, take a business class or two, or any number of other things that might help with your application in the future. I wouldn't spend all your time shooting for the GMAT stars with a 780, b/c often times to improve from a 710 to a 730 or 740 is no guarantee and can take a VERY VERY long time if a 710 came after a lot of studying.
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