There are some positions that is very difficult to get someone who can actually do better there for a team. Rodrygo's position is that type of position. It is rare to see someone like Rodrygo to fit in a team like Real Madrid and do better.
I doubt Real Madrid will accept any offer right now for Rodrygo. The club is very comfortable financially if not i would say that could be a reason for them to sell the player.
On personal reasons, there are more reason why Rodrygo will not choose to leave as well. One good reason is the fact that he can win more title easily in the LaLiga with his fellow team mater.
I see this move as an unwise move for Liverpool because mo Salah is still at his peak of his game, and he is not slowing down right now, so why not give him at least a three year contract, then after then they might decide to sign someone younger to replace him, because as it stands right now, even Rodrigo is no where near the level of mo Salah, so it will be a downgrade signing Rodrigo now to replace mo Salah because they are actually not on the same level as of quality right now in all ramifications.
Then talking about the transfer fee needed to sign Rodrigo from real madrid, I think that it's unrealistic because you can't spend so much on a player that you are not that sure that will blend into the English premier league so easily, but if it truly happens, it would be the most stupid decision making from Liverpool ever.