There are a lot of 30 dollar air brushes that will do as good of a job as anything that 5 years ago would have cost well over a hundred dollars. So do not be afraid of the inexpensive brushes out there, IMHO They are not the best but unless you are really an artist, you will not be able to use the features of the high end guns.
I started with a Badger 150
http://www.amazon.com/s/?ie=UTF8&ke...hvptwo=&hvqmt=e&hvdev=c&ref=pd_sl_mdd44pzrl_e
Still use it a lot. For general purpose layering and overall painting.
I bought a inexpensive one on
http://www.ebay.com/itm/330947419594?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
That I tend to use more and more when I want very fine detail.
I did buy a 6.99 POS at Harbor freight that is great for priming and not much else but it does lay on the primer, is easy to clean and a bit more forgiving if you get sloppy with your cleaning
Biggest thing I've learned about air brushing is clean, clean , clean get some paint strainers and use religiously. I made a bunch out of a pair of the wifes old hose and some cheap funnels. Learn to thin the paint properly and keep your gun clean. did I mention clean.
Air brush painting requires patience bunch of light coats with a flash dry between coats or you will not get the desired results.
FYI I am in the latest jig swap and will be air brushing my jigs. I love the versatility of an air brush and have been trying to develop the skills needed to paint smaller jigs for the swap I am doing a 1/8 ounce minnow head which I feel I can work with. The 1/16 are pushing my skills and patience but I have made some nice ones.
Feel free to PM me if you need an opinion or want some help getting started.