We keep saying he will "surely" prefer to go there but we still do not know how much Real Madrid wants him. We think that we are going to be able to see this changing a bit and should be important to remember that if they do not want him all that much, I mean they may want him but not enough to pay him 60 million a year for example, that's more than anyone gets in double, the most anyone gets was like 20-25 if I am not wrong, so they may not want to pay 60 for a single player and if that's the case then I would guess that it is not going to be all that easy to handle for the negotiation talks for Mbappe as well.
Maybe getting 30-40 million from them may not be all that acceptable for him when he can get 50+ from another team. Just this summer he was offered 700, sure he rejected it, but it may not be all that easy to reject it when it is so real on the table this time around.
I think if Real Madrid want to sign Mbappe in this winter transfer window they will have to spend quite a lot of money if they don't want to wait until Mbappe is a free agent. But Real Madrid has quite healthy finances, so their squad situation really needs a productive sticker, so it's possible that Real Madrid management will try hard to improve their weaknesses in this winter's transfer window. Mbappe really has a dream of joining Real Madrid, especially since he really wants the UCL trophy and it can be achieved if he joins Real Madrid.
The issue of salary is of course a big consideration for the agreement between both parties. I even think that if Real Madrid want Mbappe to accept their offer, they will have to give him a salary that is equivalent to or like the salary he currently receives at PSG. If we talk about salary, Mbappe has the highest salary at the moment, even if he accepted Al Hilal's offer last season, he would have listed himself as a football player with a fairly large salary at the moment.