Hi ManyataM,
Many GMATers use a combination of study materials as they prepare for the GMAT, so if you're planning to restrict your studies to just a single product, then there will likely be a limit to how much you improve. In addition, many Test Takers spend 3 months (or more) of consistent study time before they hit their 'peak' scores. While your current timeline gives you about 3 months of study time, the 750+ Score Goal is approximately the 98th percentile - meaning that 98% of Test Takers never score that high (regardless of how long they study or the number of times that they take the GMAT). Thankfully, NO Business School requires a score that high - so it's important to realize that the score that you "want" and the score that you "need" are not the same thing.
Since it sounds like you're just beginning your studies, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can take 2 for free at
www.mba.com (and they come with some additional practice materials). If you want to do a little studying first, so that you can familiarize yourself with the basic content and question types, then that's okay - but you shouldn't wait too long to take that initial CAT. That score will give us a good sense of your natural strengths and weaknesses and will help provide a basis for comparison as you continue to study. A FULL CAT takes about 3.5 hours to complete, so make sure that you've set aside enough time to take it in one sitting. Once you have those scores, you should report back here and we can come up with a study plan.
I'd like to know a bit more about your timeline and goals:
1) When are you planning to apply to Business School?
2) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich