Okay -- this is going to be a bit risky to post... and I'm sure it will also be controversial... but here goes nothing.
A buddy of mine does everything on a budget... he has a two car garage and didn't want to take up a bunch of foot print for a compressor.
He used several 10 foot lengths of
schedule 80 thick wall 6" PVC pipe plumbed together in a series as his "tank" -- he stuck these up in the attic crawl space.... and his "compressor" was a real good commercial motor and pump that produced plenty of air. His regulator controlled the "tank" psi to 125.
Schedule 80 pipe is good enough to hold 125 lbs (our working pressures)... but Google the ratings because this varies depending on the diameter of the piping and it's rating goes DOWN with diameter!
My guess is -- he spent as much on all the pipe and fittings and pump etc as he could have just gone out and bought a good compressor!