How have you prepared up to now, and where do you strengths and weaknesses lie? What kinds of questions are you getting right, and what are you getting wrong?
I don't know if you need an advanced course -- as you're not scoring at a level in verbal that reflects what an advanced course addresses. Advanced courses will look at the most difficult questions. You haven't yet reached that, but rather, you need to comprehend and perform better on the basics, medium AND difficult level questions.
You should consider whether you want a a classroom experience or one-on-one. Classroom based courses will cover predetermined material, and one-on-one might give you more flexibility and depth, which you most likely need. It is often the best ROI, particularly when a student has unique challenges.
Regardless of what you choose, seek out programs or tutors with a track record for working with, and having success, with the challenges a non-native English speaker faces. These are different from the native English speaker. Which is why we recommend non-native English speakers engage in an approach SPECIFICALLY CUSTOMIZED for them: non-native English speakers.
What we do at TPNY is look at the three types of English speakers: native with an understanding of the difference between written and spoken english, native with less or no understanding between written and spoken, and non-native. Our specialists, and our material, differentiate between these three test takers, because, simply, there are different ways to approach the question sets based on your proclivities. While the material is the same, its the approach to answering and engaging with the questions that is different.
Take stock in what you need to improve, and find a solution that addresses it!
Best,