There are lots of different reasons why a course might not be right for you. For example, you have unconventional needs or you work better doing self study. One thing that should not hold you back from taking a course is the pure cost of the course. Your investment in your GMAT score is a small fraction of your overall investment for B school. You shouldn’t be counting pennies when it comes to scoring well on the GMAT. A good GMAT score not only opens doors to the more completive schools and thus higher paying jobs, but also it can qualify you for a greater number of scholarships. A good GMAT score can actually save you tens of thousands of dollars in tuition.
If you decide that self-studying is right for you, then you will definitely need to invest in a comprehensive strategy guide set. There is a lot of content and strategy to learn, which you cannot learn all on your own. I would recommend creating a study plan that starts off going through the entire set of books (both Manhattan GMAT and Veritas Prep books are very good). After you complete the books, you should then practice your skills by going through the official guides from GMAC, focusing particularly on the practice problems.
If you have unconventional needs, you may want to get a tutor to help you identify your weaknesses. As every student is different, a tutor is often a great option to get individualized attention, instead of having to share their instructor’s attention with other students. One important question to ask any potential tutor is: how individualized is your tutoring plan? For example, do they have a set lesson plan that they go through with each student or do they create each lesson based on that student’s needs? It is important to find a tutor that will work with you and your specific needs, otherwise it defeats the purpose of paying the extra money.