Now that I think more about it, it really isn't even that crazy expensive.
I have to take into consideration that my only reason for going with a compressor as large as I have, is so that I could run a Dynabrade.
Between the cost of an 80 gallon compressor, the cost of wiring such a beast, the floor space it takes up, the cost of a Dynabrade (hey, those aren't cheap either), and the compressor noise while sanding, I could easily have bought a 60 gallon compressor to run my impact tools, die grinders, and nailers, and still have had plenty of money for one of these (or two, if I used the retail price difference between a 60 and 80 gallon compressor, and don't take into consideration the deal I got on mine).
Well made pneumatic motors have a lifespan (especially in harsh environments) that is legendary, but DC brushless are just as good.
Now, the downsides:
My old Dynabrade is 10000 RPM (same speed as the Ceros). My new one is 12000RPM.
The Ceros voltage is low, so it is probably safe to use to some degree for wet sanding (I guess it would be good for any automotive purpose), but when I use my Dynabrade with diamond pads on granite, I'm showering it with water, and that's more than I'd be comfortable with, with any electric tool.