Some comments about the advertisement descriptions:

"According to the "Pingame Journal", this is one of the most rare production Gotlieb pinball machines ever produced, at only 110 units made."
Does rare always = valuable?
If a particular line of machines had a very low factory run that means dealers weren't buying them. Apparently they weren't making money because people weren't playing (dropping quarters in) them.

"Add a ball" games are more fun to play then "replay" machines, especially when they are in the home, set on freeplay."
Well, I guess this is purely an arbitrary opinion. How many of our regular pins do we have adjusted to win extra balls instead of games because it's more fun that way?

"The backglass has only 2 small areas of paint missing."
"The playfield has almost no wear."
"The cabinet has the usual fading, and chipping..."
"There is also a linear cabinet crack on one side"
"...all of the contacts and mechanics are set correctly, they just may need a good cleaning."

So this pin has a flaking back glass and spots of missing paint, a PF which is worn to a degree, a faded, cracked cabinet, an unknown game count and non-working.

$1,626.99???
:-0
This only goes to show how *anything* can be worth what someone is willing to pay for it.