Price transparency? What does this mean and how can we get it?

When you go in to a car repair shop and ask how much it costs to replace the brakes you get a quote that includes everything out the door. You not only get a price but you get a price that is meaningful to you. Meaning they don't tell you well the brakes will probably cost $50 but we don't know how much the labor or additional parts may be. In fact some states have rigorous laws detailing how this must all be done up front and signed by the customer before any work can begin. How come when you go into a doctor's office or a hospital you have to sign a blanket authorization form without any particular procedure or dollar cap? What they can't figure out how much they are going to charge you? Or they don't want you to know how much this is costing you or your insurance?