Cartier has a nice catalog. I grabbed it at the store.

I'm new to this..., but that fixed price argument sounds like getting new brakes for your car and always including new rotors just in case when you really only need them every second or third time. Why are you paying for parts you don't need? If at the end of servicing it doesn't need new parts, do you get a partial refund? Please help me educate myself. What am I missing?