Can't believe they are worth that much. https://www.ebay.com/itm/325234549718?hash=item4bb97d63d6:g:C7QAAOSwwN9io5HA&LH_Auction=1
Their only worth that much if someone buys them. There are always some people who want exorbitant prices for the things they possess...
Here is another from the same seller. 5K for a core: https://www.ebay.com/itm/363761226449?hash=item54b1dbd2d1:g:Vq0AAOSwjfJiFm8U