Got two videos on my youtube channel
here i explain my airbrushes i use
http://www.youtube.com/watch?v=MFhzz...ure=plpp_video
this is my compressor i use, which is like $400
http://www.youtube.com/watch?v=JVt6U...ure=plpp_video
you can start off with one of those kits on ebay, but those compresors are not good for and if you really get into airbrushing. Badger 150 is not that good compared to badger 2020 or the renegade line.
Iwata makes much better brushes tho, with a badger you will end up buying needles and parts thu out your airbrushing when i had yet to buy parts for my iwatas.
sometimes buying a better brush for $130-200 is better in the long run.
so if you are worried you may not stick with things, try a set off ebay that comes with those crappy compressors and a cheap brush.
jerseyfest had a painting class this year that you missed out on, not only do you get to learn stuff with the class you walk home with a compressor and airbrush.
http://jerseyfestfair.com/?page_id=47