I work, part time, in the motor trade, so I get my pads for a few quid but I don't change them for the sake of changing them. The calipers are removed, cleaned and lubricated every service, which with my reduced mileage since retiring, is about every 6K. I used to do rolling maintenance on my vehicles, but now just get my son-in-law to do a major service, once a year. He is a motor mechanic, employed as such, and at my behest does everything I would do myself. Nowadays I am his apprentice/gofer/general dogsbody!