Oooo.... That is a touchy subject. The value of a working machine is high because it is working but it is not as high as one may think. It is not like a certain Ferrari Dino series which only 6 were made.
Consider this - the original price of the machine when it was sold, minus 10% for every year until on the 10th year is is worthless - $0. (This is insurance and FEMA recovery rates of lost items.) But after that is the machine has some value? I think it does. What does it cost to replace it? What does cost to repair it? Are there special things about it? What values are collectors and people like us put it at? How much you got it on ebay at that condition? And are you getting some use out of it, even fun? There is the value of the machine. You might have to wait 100 years for it to go at the original price, but what it is worth now, you got something.