Ok so this is a wild thread...
Labor rates vary from state to state or country. You can actually look up what the average hourly shop rate is in most states.
Almost ALL shops use the flat rate guide to determine what the service time will be. It does not matter if an Auto Technician can do the job listed for 2 hours in an hour. But there are two guides one is for none warranty work and the other is for warranty work. This gives better shop a little bringing to help a customer or to build a relationship with that customer for future service needs. Don't count on this little discount and I would not ask for it directly. But you can word things like can you help me out a little with the total?
OEM part not superior to many aftermarket OE brake parts. It is a MYTH. In most cases when the warranty is up there really is no reason to use brake rotos, drums and pads fro the Dealer.
DO NOT BRING YOUR OWN PARTS for a brake job at a shop unless you have a clear understanding what they will and will not cover regarding a warranty issue.
Speaking of parts.... really, I did not read aside from a few mentioning dealer parts what brand and in the brand which pads were being chosen for the estimate. Like everything there are different type material that does different things along with longevity, braking potential and brake dust and noise .
DON"T tell a shop how to do a procedure or remind them of procedures. We know what we are doing or we wouldn't be in the business to do and advertise BRAKE SERVICE!
The one funny comment is about brake rotors being thin..... no they are not "thin" even aftermarket because as far as I am aware there are NO companies even from China that do not at least use OEM specification for the basic rotor manufactured.
Grooves formed a pattern between the pad and the rotor as they wear together. By only changing the pad and not replacing the rotor will simply wear the pattern of the rotor into the new pad. The highest and best braking is a rotor surface that is flat and free from grooves to mate with a flat pad.
Many shops do not service rotors by machining them or turning them as it was years ago. Most of the time it is not cost effective and easier and quicker to change a rotor rather machine it. You can ask for the price cost difference if the shop has a brake Layth for machining rotors.
Brakes are not as easy to do as they were 2-3 decades ago, so while I know there are some good do-it-yourselfers on this forum if you don't have the tools and have not done a brake job lately it is best not to practice on your MAZDA. Unless you have a friend that sort of knows what they are doing to help you.
I am just saying just another response to read and at least think about...