Paris is and has never been a potential destination for Erling Haaland and he has said that publicly, or at least implied it. He said for him it is either the Premier League, La Liga or the Bundesliga. He never spoke about PSG being on his list. 133 million Pounds for Osimhen usually sounds more than right, we just have the problem that the market is spoiled with transfer fees like that for Neymar back in the days. 133 million Pounds is about 150 million Euro. I guess there would also be bonuses dependent on success so selling him will end in a great deal for Napoli. The problem is that you can't replace him.
Chances are this is only an initial offer but it is as you say, in this case it is unlikely he will leave and Napoli let him go for that price.
Even though sometimes no one knows what will happen in the future, the price is fairly minimal with Osimhen's current performance.
On the other hand, other teams are still expecting him, of course they will prioritize if the price is like that.
On the other hand, actually to see the probability of this, I still feel that Osimhen will consider it, but whether or not this will happen, I am still very doubtful about it.
Napoli still has the upper hand in the negotiations as they signed him until 2025. Unless he starts some wild boycott as we have seen with other players, Napoli does have a chance to keep him for another season without risking to lose a lot of money. Unless he stops performing of course, that would harm the price accordingly, but I don't expect that to happen. As has been said here, Osimhen is the gem of the upcoming transfer window and it is never easy to be bidding for a gem because all the big clubs with the deepest pockets are ready to throw their bid in as well. It is very likely that we will either see him in Madrid or more likely in the Premier League. He won't go to France and I also doubt that Bayern Munich has a chance to sign him. They could urgently need him, but Osimhen can ask almost any salary and Bayern won't do that.