I agree with zach's summary above - I'm someone that didn't play pinball a lot when I was younger. When I started getting serious about pinball, I wanted to experience all of the games I could and realized I couldn't get a good feel of them in a bar. I found that having the game in your house made a big difference. Having a walk out basement really helped b/c moving these things is a pain (literally).
Now that I've gone through many of the machines, I'm circling back and buying the ones I really enjoyed (top quality if possible). I'm also the only pinball person in the family so if I had the ability to keep more than a handful, I would have. Unfortunately I couldn't so I needed to move in and move out.
I also enjoy the hunt. If I didn't, I couldn't accomplish all that I have. Meeting some very nice people along the way too.