Don't have any silver coins for sale but a bunch of circulated Great British Pounds that are kind of collectible. As in the coins which have rarer designs on them.
You should post this in the auction sub forum as this post can be deleted should someone take control of your account. Posts in the auctions sub can't be edited or deleted by the user.
Not sure if its been suggested but you could fill a briefcase with newspapers and then just put a top layer of bank notes on top for the photo kind of like that cricket dude did.
Guess we'll have to wait. The guy could have also artificially set the market price by setting a higher BIN and chancing it. You'd need more than one to be sold to determine a true market price.