Quoted from Tsskinne:

I'm young, relatively poor (I teach high school) and I have been able to put together a nice little collection in under two years just by purchasing games that were cheap fixing them and selling for profit later. Check craigslist often, negotiate, and take a few chances. It is a great hobby. Also if you are willing to drive and do the transporting of games that makes everything easier. I do work a second job mostly to fund my pinball hobby, but that is by choice. In addition to that I have met incredible people in this hobby, some of the nicest, most sincere, and helpful people I have ever encountered. Warning though it wont stop with one game.