Set of Past Exams for Exam 5

[Scheffe]

In the CAS online store, I find the "Set of Past Exams for Exam 5".
Does it worthying to buy the Set of Past Exams for Exam 5?
Is it useful?
What does it include in the book?

I find some past exams in CAS web and they are free.

Thank you.

[Avi]

All old CAS Part 5 exams can be downloaded for free from here:

http://www.casact.org/admissions/studytools/exam5/