I second Al Hockenbery's advice. I have 4 airbrushes. A Master purchased off Amazon for around $50; an Iwata Hi-Line purchased from Binh Pho, and 2 Grex TG3 from Joe Fleming (who acquired the line after David Nittmann passed.) The Master airbrush never worked. I spent more time trying to get it to work, and never really learned how to use an airbrush. The Iwata was a very good quality airbrush, but using the trigger mechanism, that uses the index finger on top of the brush (most common among brushes at that time, as well as to date) never worked for me. Despite 2-3 years of trying, I could never develop the right control/finger dexterity to accomplish what I needed to do.
In 2014, I attended the AAW Symposium in Phoenix where Joe Fleming was demonstrating airbrush basics. During that demo, he was using a Grex airbrush that the late David Nittmann was selling in his booth in the trade show. Joe had never used it before that demo, but watching him use it during the demo led me to Nittmann's booth right after the demo. The key that sold me on that airbrush (and yes, I bought one) was the trigger mechanism was akin to pulling a trigger. That mechanical use was more comfortable for me; in a few minutes of playing, I was able to write my name - cursive - in very small lines. Disclaimer - there are firearms in the house and I can shoot - but have not fired a gun in 30 years? The point I'm making is that the trigger mechanism is easier to control, and the majority of people can adapt quickly to that. I've noted that Iwata now has a line of airbrushes that feature the trigger mechanism - Neo. I would expect that other airbrush makers will develop a line to include the trigger mechanism.
Are these airbrushes cheap? No. Expect to pay in the area of $200, plus. But I found that in this very specific area, trying to do it on the cheap will result in a lot of frustration.