Two mechanics have told me that I need to replace my compressor.

What is your question?

One of them told me that if I didn't my serpentine belt will come off and the vehicle wouldn't run at all. His price to replace it is $600. The other told me that I can still drive it & just replace it when the belt comes off? His price for labor is $50. I don't believe anything that either of them say. I have called various auto parts stores in my area and nearly all of them tell me that I must replace the compressor, accumulator, and orifice tube in order for the compressor to be warrantied. I've also called several salvage yards regarding these parts. I have several questions: Is it necessary to replace all three parts? Is it ok to buy the parts used or will this eventually lead me to replacing them again? Can this car be driven to the shop or should it be towed? Roughly how long does it take to make this type of repair? Roughly how much should I expect to pay for labor for this type of job?