1 of 15 VS 1 of 15,000 it is a no brainer that this machine as with any rare prototype is worth more than a production game with thousands available to collectors, and if anyone believes they are Not worth more money they are delusional. The fact that most punters wouldn't pay a premium is irrelevant because only a very small percentage of collectors are needed to drive the price up on rare collectables as they only appear infrequently.
So if prototypes are less than 0.01 % of all pinball machines out on the market and most are tightly held by the designers and engineers these are extremely rare. Pinball legend Ted Estes posting here is testament to the historic and nostalgic value these have for some, and for others it is just another beater TZ. Having said that a premium will be achieved for this, But a $55,000 premium is definitely a stretch.
Terry.