Same as anything. It will sell at the right price.
The right price for some guns is only about 50 cents & that is why they linger so long. Their problems rectified overcome their terminal value. In other words, an insurance write off.
Some others are priced at the very top of the market, ever.
Good guns, yes, but at that price you could buy five or six very nice guns from elsewhere
Recently I saw two guns come up for sale that interested me & in both cases they had sold on the same day they were advertised.
There are plenty of discerning buyers out there.

Some lingerers are a Purdey light game 2/12 chambers @ $52,000.
A Holland & Holland @ $98,000.
A Greener blue rock @ $6,500
An old junky revived from the dead Purdy hammer gun with sleeved barrels @ $10,000.
O.M