I believe in a marketplace, money can do everything. It is not going to be impossible for Manchester City to let Haaland go if the money is really good. But I wonder if Real Madrid is going to offer that much money if they actually get Mbappé for something less than what they will need to offer for Haaland. He's in good form. And that is the only reason he might not want to make any changes right now. But who does not want to play for Real Madrid?
Quality over money, if Real Madrid wants to go after a player for the potential the player possesses, they should not put money first, otherwise they will lose the player and miss out on filling the void the player will cover that season. Whether it's Haaland or Mbappe, I believe any of them can fit in, but they should prioritize the player who truly wants to build a more prosperous career with Real Madrid over the one who needs convincing to join the team.