Dude - Keep it simple!
Your views on pinball are wide open and you created huge grey areas with your ideas of "buying 3 pins" and "Dmd's are going to crash".
If you are opening a restaurant chances are you probably would not come in saying "I want to open three restaurants, all with different styles, and I think that this salad thing is going to crash because a steak just looks and tastes better"

Keep it simple list-
1. You have money (it seems) - awsome!
2. You like collecting fun items you can play (vids) - check!
3. Go play tons of pins and do research - check and check!
4. Buy one and get playing. Your list of games you have played is awsome.
5. Play your home pin and see if you like it.
6. If you enjoy it buy one more. You can trade them out also for around what you put into them.
7. If you don't enjoy pinball sell your pin and move on. Not likely.

Put aside over thinking with your "I must find the 3 golden pins" attitude and collectable economic theories and just buy an AC/DC and have a blast.
Enjoy the ride