As a working professional, your time may be limited. You'll want to be able to balance both work and study without making yourself go insane.
You're on the right track in terms of searching for a mentor. While the best solution may be an in-person private tutor, you may also find it to be the most expensive option as well.
Consider your learning style and the budget you have. Online video courses are a significantly less expensive and perhaps more effective way of learning - as long as your internet connection is reliable. Take a few minutes to think about how you best learn and then weigh in the cost component. If you're a visually inclined learner who needs someone to walk you through every single question - take a look at the free videos at GMAT Pill
On the other hand, if you really need that in-person interaction, private tutoring may be the way to go. But keep in mind private tutoring involves scheduling with your tutor and lots of logistics that eat up your time. If you're about efficiency, you'll want something online.
Hope that helps!
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