Cheap Airbrush
I agree. you'll want to start out with a fairly cheap airbrush, but don't get too cheap. You may also want to just try a spray can of paint. They may work well enough since your just starting out and your design is probably fairly simple. I have a Badger 360 and although it is an execellent airbrush, I still like the simplicity of a paint can (no mixing, assembly, and much less clean up)