I would propose an answer only for the last part of your question "Why should we pay so much for Cisco certification?"
I believe it is because with Cisco certification you can easily get a good job because you are demonstrating a basic level of IP competence. Not necessarily in an ISP or a System Integrator, but also in a Call Center and similar companies. Needless to say that Cisco has a tremendous market share. Moreover, it's increasingly considered a competitor for Telecom companies as well because we are in era where many technologies are shifting towards all-IP.