With him not wanting to extend his contract at PSG and also snub a move to Saudi Arabian Club, it seems Mbappe no longer prioritizes money above all else. By joining Real Madrid, it is clear that he wants his career to shine even more and get the opportunity to reach achievements that he never felt when he was with PSG.
Apart from that, Real Madrid was one of his childhood dreams and it seems that this is also one of the reasons why he refused a contract extension and chose to go to Real Madrid. Maybe he thought that if he missed that opportunity, Real Madrid might not give him another chance because he once made Real Madrid very disappointed at times he preferred money over the opportunity to have a more glorious career.
Previously of course, the money and facilities he would get were the reason Mbappe stayed at PSG,when the agreement between Madrid and Mbappe was almost happening, Mbappe changed his mind after accepting the contract extension proposal given by PSG, in addition to getting a very large salary, facilities and also special privileges from PSG made Mbappe finally extend the contract, Mbappe at that time got privileges that were never obtained by other players including Messi so far, yes Mbappe got special rights to determine prospective coaches, prospective players and also fired the coach from PSG and of course it made his ego bigger at PSG at that time.
At this time of course mbappe has opened his eyes if money is not everything, mbappe to madrid of course with the aim of getting the champions league trophy which indeed during his career he has not gotten, besides that new experience of course he will get by playing in a league that is indeed more competitive compared to Ligue 1 so far, if indeed the reason for moving is just for money of course he does not need to go to Arabia because it is reported that PSG are ready to pay Mbappe salary is bigger than he's got this season in PSG.