Don't think so, his current market value is way lower, probably not over 100 mil.
He will be a free agent in 6 months.
Since his contract is almost over, I agree that his market value even below €100m. Real Madrid must prefer to wait for 6 months, until the end of his contract. If Real Madrid tries to sign him in January, probably there is another drama with Mbappe. It is better to be patience, 6 months isn't a very long time to wait for Mbappe.
Of course, the market value will decrease because currently Mbappe cannot achieve success like the 2018/19 season, which led France to win the World Cup and Mbappe won the title of best youngest player.
Now with PSG he doesn't get anything except the Ligue 1 title.
Mbappe gets difficulty to succeed like in 2018/19 season, he isn't in a lucky condition lately. He lost some good teammates in PSG, Messi and some great players are leaving PSG. There is also no big competition yet, Mbappe only focus on domestic competition. Sure, Mbappe probably can win the Ligue 1 trophy only.