I think its more likely the Large rose he overpaid for when he bought it , it has been for sale over two years.
The same seller has recently added one on his website in fine grade for £100 and the more expensive one maybe he bought attributed and just gave it a go.
Some copper pennies sellers have found not attributed and not paid much for them ,its therefore much easier to sell them cheaply.
Dealers who buy quite a lot may just take a chance and pay a high price for something considered rare / scarce hoping to sell it and just make a bit ,it doesnt always work.