Found them on eBay:
https://www.ebay.co.uk/itm/185422320567Pictured "CoA" states 0.999 silver (and no weight), but if you buy 3 (1 for 17.38 GBP), you'd get actually below the current market price of silver.
Further description probably explains it as it says "stunning real .999 Silver plated souvenir".
"Incredible detail and etchings you won't find this anywhere else" - yeah, right.
If you go directly to their site, you get even lower price (1 for 9.95 GBP):
https://www.hattonsouvenirs.com/product/bitcoin-silver-coin/There the description reads "stunning .999 silver souvenir".
I very much doubt there are two different coins; I'd say they are covering their ass as not to violate eBay conditions, but shady as hell.
Also, just based on that video, I severely dislike the guy...