You bought a watch from the original owner and took a gamble. The lack of better dial pics was likely a reason it didn't go higher, which was working in your favour.
Had it been from a dealer, I'd say get a return case open. However, as it's from the original owner, I generally consider these as 'pays your money and takes your chance'. You'd have been over the moon had you got a bargain because of the bad dial pics. Can't have it both ways.
I'm thinking of offering to cover part of the seller's listing fees. I think that would be more than convincing to an honest seller.