Im not really too fussed about condition considering that it is so rare, really as long as its in decent nick and doesnt smell of cats I would be happy to take one
There is one second hand one going on ebay now for about 330 quid that isn't complete and I am not too sure if it is a decent price or not, might even be the 500 one you saw discounted. No idea what the market/worth would be for something like this, but I think it was around 300 Euros the last guestimate I got
. But as with everything in life, something is only worth what someone is willing to pay for it.
I think its a longshot too, but hey you dont win the lottery if you dont buy a ticket