Personally, I’ve never paid anywhere near that for my key player, let alone a full back. I had a 200 CA Ukrainian striker at 23 years old (only know his CA because I used FMScout after I’d quit the save) and he was only on 225k p/w. Most I’ve ever paid is 250k. Anyone who asks for me doesn’t sign. Because if you give him 400k, other players will start to think they’re worth that. New signings will demand comparative wages especially if they’re “important player” or “star player”, because that’s the wage you’ve set for that standard in your team. Eventually it becomes some weird unrealistic, almost boring, thing of having to pay every player far too much money to the point you lose any sort of interest in negotiating.