I just finished taking a GRE prep course with Princeton Review and though I feel the course is very expensive, especially for those looking into going back to school and braving student loans again, its worth the time and energy. My instructor was extremely helpful and the little tricks they teach you will no doubt help your score. If you have the extra cash and you're looking to go back to school, I encourage you to use Princeton Review.
*Note: I haven't taken my actual GRE yet, so my review may change depending on my score.
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