Just do it, especially if you've been stuck on the same score

I had prepared on my own using the Manhattan Prep Interact (on demand) option for two months. However, I never really found improvement. I constantly got 650s on all of my practice tests and on the actual exam. However, I switched to the live online advanced course (to help those struggling to break the 700 barrier), and it was a tremendous help. My instructor, Mark, was very knowledgeable, enthusiastic, and offered great strategy and advice. It was a lot of fun going to class. At the end of the course, I took the GMAT again and was able to break the 700 barrier. Manhattan Prep is correctly referred to as the gold standard of GMAT Prep. It was such a big help. Definitely upgrade to the live online class