Getting ready for certification exam

[Qka]

I am in my final semester and getting info about certification. Trying to save money...:) If I can... So, I am thinking to purchase a used review course with CDs. It is like 50% cheaper than original. But it seems like the only available reviews are from 2014. Is there much difference with 2015? How to find this out? Also, a friend of mine just gave me her CDs but they are dated like 2011 or 2012. Is it too outdated?

The second question is if my friends and I are going to study in a group, any suggestions with the plan of study? We plan to buy different reviews and exchange. They are pretty expensive and this way we can use different reviews. Any other ideas how to study?

Any info would be very appreciated. Thanks!