Im totally fall in love for this game and now im playing 2055.
However, when i wanted to keep those highly rated players, they will request the unrealistic figure (sometime request more than 400k).
But when other team sign the player, they able to sign him with 200k+.
May i know is it a game bug or has some hidden nego skill / tactic in this game?

Best suggestion i can give is at the begining of the season before buying additional players ask the board for more wage and funds (or just wage if thats all they will give you). from there check your squad for players contracts that end the following year and offer them a contract there and then.
I find that they are not as unrealistic with their demands if you offer it earlier then say the last transfer window or close to the end of their final season. Plus if your clever enough you can offer them less than their request to save some wage funds.
Let me know if this helps.