My perspective.
I'm interested in MM.....but not for 8k+. (At the moment)
When and if I do enter the market for an MM I'd be MORE likely to look for a nice MMr to purchase vs a 20 year old original. (Assuming they are of decent quality).
Nothing against William's at all.....I LOVE William's games. 3 of my 5 pins are William's and those three are my favorites.
But...this isn't comics or cars....this is pinball. I'll take 20 years newer every day of the week and twice on Sunday.