Mainframes are expensive because it’s the main part of operating systems.
Yes I do use a mainframe in my daily life. When I’m on any social networking site, WikiAnswers, or Wikipedia, I’m using a mainframe.
The mainframes hold approximately 70% of the entire data stored on Earth. It takes 3 full days for a mainframe to get up and running. Earlier mainframes were provided with cool pipes through which cold water was passed to cool the system. Most of the people working on a mainframe has never seen the mainframe.