One of the hardest things to master in pinball is the "dead flip", also known as the "dead bounce" or "bounce pass". It's the art of strategically doing nothing:
I think it's equally hard to apply to dead flip technique to collecting. If you can own a game for more than a year and spend less than $50 on it, you've mastered the collector dead flip. I've only done this with a few games, and usually that was because new parts were simply not available.
I bring this up because I just bought a nice, fully-working "The Shadow" for a good price (I think): $2700. I want to replace the head decals, plastics and translite, and add some LEDs and a ColorDMD. That would make it a $3600 game. I'm already thinking about this, even before getting the game set up. That's not much different than a kid who walks up to a game, hits the start button 4 times and hits both flipper buttons repeatedly.
I really want to learn the collector dead flip. I lost $700 selling my last game, because I gave it too much love. This time around, I want to do as much as I can to restore the game without spending money, and then think about next steps.