Could you please tell from where and for how much you got Knewton course and Grockit course?
1. Knewton - Used the GMATClub promotional voucher so got 100$ off the 690$. Paid 590$. But remember- they have a 50 point guarantee, so if you do well on their diagnostic or do not score 50 points more than your baseline score, you get a full refund.
2. Grockit - I purchased this before they reorganized the website and the prices. I used a voucher from the Stacy Blackman blog and got it for 39$ - totally worth it for the amount I used that website.
Also, did you do the AWA for every practice test?
To be honest, I only did about 4 CATs with the AWAs. I did about 18 CATs in total, so a lot of them without it. Knewton for example doesn't even offer an AWA section on its CATs. I recommend that if you are going to do a LOT of CATs like I did, then you can skip the AWA for about half of them or more, depending on how much time you have. Though I am a rather fast typist and have always done well on essays - I finished both essays with only 20 seconds to spare. Don't ignore them completely - have your generic answers well memorized and brush up on your debating vocabulary
The argument essay is slightly tougher than the issue one, so focus more on it.
By the way, Abhay , would you please explain more about your disclaimer: "Your GMAT score is irrelevant to who you really are, which is pure, innocent, intent-less Awareness. "
This has to do with my understanding of existence, which is based on the concept of Non-Duality. You can google it to find out more. In brief, it helps you realize that your true nature is to be the witness of your own life, rather than believe that you are the burdened doer of it all.

~Abhay
Believe those who are seeking the truth. Doubt those who find it. -- Andre Gide