I do these as a hobby, it has greatly reduced my $$$ spent on tackle over the past 6 months.
Your initial investment in this is where you spend your money. What i did is watch Ebay for a couple of weeks and check the prices of the air brush/comp kits. Do a search for finger nail painting as well, a lot of the beauty salons use the same set ups for painting fingernails, sometimes you get a better bargain.Do not go buy a comp and gun from a local retail shop, you will end up spending much much more.
I use a power cat compressor with two guns attached to it, one is a top/gravity fed and the other is a suction/bottom container fed. I added the bottom feed gun, but everything else came with the original kit.
Paint? I have several different types, but the main choice i use is Createx,(hobby Lobby) because its already set up for an airbrush. Most other paints you will have to thin out with some water.
One of the big things about painting with an airbrush that i have found is the paint you choose. I normally only have 4 colors that are opaque, the rest of my collection is transparant color, meaning i do a base coat in opaque, wheter i want the bait to be a light color or a dark color, then from there i start all the creating process. I also have several colors with Pearl already mixed into them. (Sparkle)
I also use a quart of polyurethane that i dip the lure into after the entire process is complete for the sealer coat and shine. I normally do two dips.
Some tools of the trade:
You will want to keep your eye out for certain types of patterns, such as fabric that has the scale effect, fish netting etc. You can use these as a overlay pattern, you can purchase this from hobby stores etc, at the end of the post i will post a link to Barlows tackle, you can also get all of this from them as well as the screen holder for your patterns and also the blank crank baits for painting.
You can also buy transparent tape with patterns already in them as well as holographic tape for a holograpic look to the bait.
http://www.barlowstackle.com/fishing-lure-eyes.html I really enjoy this hobby, and the more you do it the better you will get, i've seen some really nice paint jobs here on the forums and i would be glad to help you with what i can if you decide to start painting.
These were the first lures i ever painted with a airbrush. I just finished another batch over the weekend, i will try to post a tutorial with pictures on the process i use to paint one.


These are pretty basic paint jobs, but i was very proud of them, back when i began painting, i have started challenging myself to do more harder type patterns and such. Its a very relaxing hobby for me, and like i said if i can help you out i will.