even if you come up with a match, it could not even be guilty but just a way to get the poor guy banned or red trusted, there is no certainty he really owns any account till he hand it over.
At only 0.02
BTC for a green trusted Legendary account, my guess is he's just hoping to scam someone.
I've tried to pinpoint accounts from auctions before, but I never found a match.
I kinda expect a real account seller to leave out the details, say: 2400+ posts, 1600+ Activity. That protects the account. So I expect the ones with exact details to be more likely to scam instead of owning the account.