Marian, I got a Paasche Ra75 from www.Hobbylinc.com for $28.50.
This regulator is designed specifically for use with airbrushes, and is therefore calibrated in 1psi increments from 0 to 60psi. The workshop type gauges are often only graduated at between 10 -20psi increments and run to a maximum of up to 175psi.
It also includes a moisture trap, and has transformed the results I can achieve with my AB since buying it.
My advice, spend a little more that you might at Lowes, and get one of these, it really is worth the money. After all I was prepared to have mine shipped across the Atlantic because I couldn't get one in the UK!!!!!
Karl