There are still many possibilities, but I agree if PSG have to lower transfer fee that man because the price now is not very possible for Real Madrid to sign him. Although Real Madrid has a lot of money, but the previous Bellingham transfer fee may have burden their finances. Actually, if another club brave to recruit Mbappe at current prices then PSG will be ready to let him go, if that happens Real Madrid will wait again to sign that man.
I think possible price for Mbappe around 100 million euro and Real Madrid looks won't pay higher offer fees transfer above 200 million euro due not beneficial position for PSG. Current Mbappe contract expiry next season there are not many option for PSG, if want sell Mbappe with lower price is possibility but difficult to sell him with 200 million euro and interested teams want sign Mbappe prefer waiting until his contract over next year and become free agent.
Madrid is in a quite advantageous position with Mbappe's current condition, but if an agreement is reached to renew the contract it will be very difficult for Madrid to bring in Mbappe next season.