Certification exams could be difficult to pass if you try to gain all the knowledge available about a particular exam. There is massive stuff available for top exams, but do you really need to know everything? Even the official textbooks are thicker than dictionaries.
Some students make their life difficult by trying to learn everything about a particular exam. But unfortunately examiner is only interested to know if you can answer the questions or not. The examiner is not interested at all in how much knowledge you have or how many books you have digested.
That is why a tuition provider and a cheap one who could provide a good number of questions and answers for you to pass the certification is all you need for your exams. You can find plenty of good tuition providers on
http://www.certifyglobal.com