There are 3 main values. Well, 4 really:
Insured Value - the amount required to buy a replacement - often at top dollar, plus costs involved in replacement. The latter can exceed
the actual purchase price.
True Value - The marketplace decides. Auctions usually set the bench-mark. Ignore major aberations such as top end blow-outs and bottom end flops.
Scrap Value - Whatever you can get for it at the recyclers.
Nostalgic Value - Sometimes priceless.
With regard to second-chance offers on Ebay. Someone bidding to $4,400, but only willing to pay $3,000........ Really? Beware of scam bidders. It is common practice for some vendors who get friends to bid on their behalf. This bumps the price up. I have encountered several sellers who have an active network for this very purpose.
David Fryer, thrice burnt in sunny Queensland...