What would a good example of this machine be worth? I know of someone who has what sounds like a really nice one that is going to be serviced next week then it will be listed on ebay for around $4000. After talking to the seller they sound genuine and the machine sounds very clean (welcomed me to come around and inspect) and I think you could secure it for around $4000 with a pre auction offer.

Private sale from a collector ? Might be worth looking at.  If you are happy to pay $4000 and you are happy with the game then you should do ok.