As a comparison, I just bought an elcheapo 95ltr compressor from Supercheap. Stripped off the 240v motor and air compressor, hooked up the wiring to the feed for the aircon compressor and fitted air line and high temp hose in between as required.
Misc bits $150
Can run air tools and sorts out my 40" tyres from 5psi to 30psi (although I have not timed it, estimate about 1.5 - 2 mins a tyre).
Ugly is a state of mind..... and the state of my truck!