Wishdiak,
I do see your point. When considering the cost to take the exams and buy training materials, some 'insurance' to make sure you actualy pass the tests is understandable. After all, who wants to spend loads of cash and get nothing for it? However, I do have some fears.
If you pass the exam, how do you know if it was the hours you spent studying that made you pass it, or the braindump?
What happens if your in the workplace and your presented with a problem that falls into a topic area that you relied on the braindump for? You may have studied the topic area but not enough, and it was only the braindump that helped you answer the corresponding questions. If this happens, you'll be stuck.
At the end of the day, if you know the subjects properly then you stand a good chance of passing the exam.