The seller, who now knows the real value of the item then chooses to sell it anyway for half it's worth, so they can get the money they need now to pay for their crack habit or whatever.
The wife and I joke that the typical story is someone coming in to sell an heirloom that’s been in the family for hundreds of years and has saved grandpa’s life in both world wars.
After all the appraisals, offers and counter offers, the seller ends up taking 20 dollars for it and is off to the nearest casino.