I think a lot of people make the mistake of debating this question too long. They end up debating this question well into their late 20's and into 30's. That dramatically closes the window of opportunity to get into top programs.
Is a top bschool MBA or any MBA for that matter, worth the cost of attendance?
Well you got to compare the opportunity cost of continuing your professional career with a MBA or without MBA degree.
If you feel that you are in an industry where a MBA degree won't affect your future income, promotion and etc - then don't bother pursuing a MBA degree.
If you feel that you will regret later on in life if you don't pursue MBA now, then you should just close your eyes, shell out money for GMAT Prep, GMAT, and bschool application related expenses.
Bschools can charge what they charge because there's demand for the program. If there's demand, then there must be a reason behind those demands.
MBA degree is a degree that intends to teach you the science of business management, operation, philosophy, technicality, number-crunching, and better decision making. It's an opportunity for you to upgrade your skills through learning, collaboration, team work, and sharing.
David Brinkley, a late American television journalist, once said, "A successful man is one who can lay a firm foundation with the bricks others have thrown at him."
MBA degree will better prepare you to "lay a firm foundation with the bricks" that life can throw at you.