I think you are asking the wrong question. The question you should be asking is "What steps allowed you your current collection of games?"
I work for a family owned wholesale distributor. It's a cool place to work and stress is kept at a minimum. I could make more $ somewhere else but I like the people I work with and the projects that come across my desk. I make enough to do the things in life that I want to do. Money is not everything.
There are a some misconceptions about "pinball enthusiests that own a bunch of cool machines".
Some people have extra income or retirement money and spend it on these things, buying 5-20 machines in a few months time.
Others started collecting 20 years ago when prices were not crazy and you could buy some great titles for 1500. Back then, there were a lot more machines than there were people that played them.
Some pinball people here were operators back in the day (some still are) and held on to some titles and are just fans of pinball. So, it was their business. There are also distributors that sell machines for a living and have a collection of games they took in on "trades".
Then you have smaller groups and some larger groups that are in leagues and play competitive pinball. A lot of those groups of people have feelers constantly out looking for other friends and trading within those groups and other social networking groups. That really helps "push the hobby wheels forward" much faster than 15 years ago. It really took a lot more time to track down the titles you were looking to buy back then.
Some enthusiasts are a combination of all these things. Most games I bought 15 years ago were in a broken state and I just taught myself how to repair them. Back then broken games were cheap because there were almost ZERO places to buy replacement boards or displays beyond eBay. If you could repair stuff back then, it was a very valuable skill. Also, I started with arcades and combined arcades and pins together at some point. Regarding the funds to pay for a hobby, I don't mix hobby money with other money. I keep these separated and when funds run low, I sell something, or find another project to work on and resell, or schedule some local repairs for $50/hr. Yes, that's cheap!
So, when you look at someone's list of titles and are like "what bank did you rob to afford 50K worth of games"... Not many people actually take that path. Sure there could be some but the vast majority of people with amazing collections of games either have money to burn or started collecting a long time ago.