The Michelin Airstops are crazy expensive. However, matched with Desser Monster retreads, I can get well over 600 hours. I just checked the tubes when I rotated the tires, and they look brand new. I will replace the tubes regardless when I replace the tires.
Simple math, as a hourly maintenance item, tubes and tires operating cost is roughly $1/hr. for me. That’s a small percentage of operating costs even with the expensive tubes.
I will mention that just because you don’t need to put air in the tires, or for those that don’t use Airstops and/or use a valve extension, pull the wheel pant routinely, at lease every few months. Inspect the tires, brakes, brake lines, etc….
In my opinion that needs to be done regardless of the tires needing air. Takes a few minutes a wheel.
I just discovered through a routine inspection one of my brake pads had an odd groove in it. The rotor had a small thin chard about a 1/16” long and a couple thousands wide. Not sure what would have caused it, stuck rock?, don’t know. I filed it off and buffed the area. Can’t even tell it was there but glad I caught it early.