I would want a regulator at least, I found a combo regulator,water filter on Ebay for less than $20. I am changing air pressure fairly regularly with different types of paints.
You can get a lure turning motor on ebay for around $20, search for rod drying motors. I got one and with little modification have a 8 lure drying system for less than $30.
I bought some parts from Mike's took over 2 weeks but all came as ordered. I get a lot of parts from these guys- http://www.southwesternparts.com/ much faster and more online schematics.