Have you asked TheQuin? He's actively managing the official FBC thread and he could ask the owner (wetsuit) if that's reasonable enough.
I wouldn't trust a random stranger claiming to sell something that doesn't belong to him/ her.
He means he wants to cheat. If he can work out the server seed from the hash he could choose a client seed to get the result he wants. Fortunately, our server seeds are so complex you would need a database with more entries than the number of atoms in the entire universe. Inventing a storage device capable of holding that would make someone so rich they would need to scam casinos.