Real Madrid has much better finances and it is possible that Haaland will be their target next season.
I don't really believe it's not about money, modern football is almost completely involved in money when it comes to player transfers and the prices are much more fantastic than expected. Real Madrid is a big club and it seems difficult for any player to refuse to join them.
Have you ever seen the Cristiano Ronaldo era where almost all the stars were there and the club's finances were still quite stable.
For me nothing is impossible and if Florentino Perez wants Haaland then I am sure he will play at Real Madrid.
It's just a matter of time and I'm pretty sure that next season Haaland will be a target for Real Madrid if his performance is still good.
Even it's possible, it would be stupid if Real Madrid sign Haaland when they already have Mbappe. If a team can automatically win any league by signing all star players, PSG already won Champions League. It's not easy to combine "2 heads" in one team, it could influence internal problem because each of them think he's the best player and his teammates need to listen to him.
Signing star player is fine as long as you sign the player that play in the same position which your team currently need it, not blindly signing star players.