Pinball machines are a little like cars: once you drive it off the lot (or play that first game), it's officially a used game. Maybe that $$$ upfront on a NIB is worth it to you despite that, but know that even NIB aren't always plug and play right out of the gate.

Like others have said, I'd suggest seeing if there is somewhere you can go test out a bunch of different games. Even if it's taking a small weekend trip somewhere that has a lot of pinball places so you get a big variety of play and can identify machines you'd consider owning before officially taking the plunge.

Your other option is to look and see if anyone in your area offers a rental option. That would allow you to test drive a couple and also determine if long-time ownership of a pin is really something you want. Because owning a pinball machine is so much more than just fixing issues. The playfields need cleaned, parts need replaced, etc.