Napoli isn't just trying to get every penny from PSG or anyone else by charging €150 million. A power move, pure and simple. Napoli knows they have leverage with Osimhen's goal-scoring ability. It's about telling the world they won't be intimidated in the transfer market, not simply the money
PSG need a good replacement for Mbappe and Osimhen is their target on the transfer market. But €150 million is a very expensive cost and if PSG agrees it, they will show their bad transfer strategies. If they had sold Mbappe to Real Madrid two seasons ago, they would have received good money to use for buying Osimhen or any other player.
Now, Lukaku. His beastness is undeniable. He differs from Osimhen. He will secure the ball, make room, and provide a lot of expertise. This doesn't replace Osimhen; it expands Napoli's offensive. The tactical shift is smart, in my opinion. And if they can shed some dead weight, even better. It frees up cash for talent acquisition and provides Conte greater freedom to create his team. Never believe anyone who says Napoli's going crazy
Lukaku can contribute many things for his club but his body is too cumbersome and it affects his speed and responses to opportunities. Lukaku can make very strong and good shots but if you expect him to do good one-touch finish in sudden chance, he will likely miss it easily.
Osimhen is different and has better ability to take advantage of such chances. If Osimhen leaves, Lukaku is a good replacement for the Nigerian player. It is important that Napoli has Kvaratskhelia who can assist Lukaku very well.