Eligibility, applications, renewal cycles and what the certificate is worth.
The exam fee is the small part. Most candidates are surprised by the standards, and by the bill that lands again three years later.
Exam guideThe exam is not offered continuously. It runs in windows, the application closes long before the window opens, and picking the wrong one changes which editions you are studying.
CareersThe honest answer is that the certificate does not set your salary. It changes which jobs will look at you at all, and that is where the money actually comes from.