Obvious advice:
1. keep playing a lot of different pins.
2. Try out the game you want before you buy it.
3. I have bought 5 NIB and 4 used in the last 2.5yrs. If you want something that likely won't need much work (see #4), get a HUO slightly used game. It may be already dialed in and have some expensive mods and you will get it for less than a stock NIB machine.
4. It's pinball. It's going to need work.
5. You're not going to get "only one pin." I'm not being funny. Just go ahead and figure out what furniture/room you're going to sacrifice next because it's going to happen.
I have had no issues with my Stern games. I wouldn't worry about that. JJP games are fun and high quality. If you have limited space, but not budget maybe you want to consider one of those.