Hi croches,
First off, a 680/Q45 is a strong score (it's right around the 85th percentile overall), so it could be enough to get you into your first-choice School. As such, a retest might not be necessary. Depending on the Schools that you plan to apply to, you would likely find it beneficial to speak with an Admissions Expert about your overall profile. There's a Forum full of them here:
https://gmatclub.com/forum/ask-admission ... tants-124/If you do choose to retest though, then it might help to see your Enhanced Score Report. While the ESR doesn't provide a lot of information, there are usually a few data points that we can use to define what you should work on. If you purchase the ESR, then I'll be happy to analyze it for you. With a Q47/V36, you don't have any big "weak spots", so it would also help to 'nitpick' your recent practice CATs - with the goal of trying to define WHY you got questions wrong. Based on your Official Scaled Scores, your content knowledge is probably fine - so there's some 'procedural' aspect to how you're answering questions, and possibly some missing Tactics, that you would need to work on to score higher.
GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. As such, this 680 could have been a 700+ relatively easily. However, at higher and higher score levels, the GMAT becomes really 'sensitive' to little mistakes on "gettable" questions, so part of your focus going forward should be on making sure that you're doing accurate work (on the PAD; NOT 'in your head') and eliminating little mistakes from your process. This is all meant to say that you might be able to raise your score on your own (t's not clear whether you actually need a tutor or not - and there are specific study materials that can help you to pick up points in the timeframe that you've described).
1) What Schools are you planning to apply to?
2) Going forward, how many hours do you think you can consistently study each week?
GMAT assassins aren't born, they're made,
Rich