How much money do you want to spend on a compressor? If you want a cheap compressor that will do the job you could find a small medical compressor at Ebaby for $10 to $40. Those medical compressor are continuous running, fairly quiet, just a little louder than an aquarium pump, and have just enough air pressure (about 15 to 20 lbs) to airbrush with (at least with my Iwata HP-B and HP-C airbrushes). A medical compressor is probably equal to the quality and life of a Testors Blue compressor.
If you want to get serious about airbrushing then consider a silent compressor. I use a SilentAire 20A silent compressor. It has a quiet refrigerator motor. The 20 in the model name means the Decibel rating…20 dB. As a comparison a whisper is 30 db. I’ve put my cell phone inside the compressor and my friend on the other end of the phone couldn’t hear the compressor going. The silent compressors will last a lifetime, can run two airbrushes, air pressure to 85 lbs., but they will cost a lot more money.
A side question. Does anyone know why compressor makers don’t put Decibel ratings on their compressor? It sure would make it easier to figure out which compressor people could live with.
How much are you willing to spend for a compressor?