I don't think Napoli is that interested in selling Osimhen. If they were, the price wouldn't be so high. They've also noticed that Osimhen's performances have declined. It's not that Osimhen isn't still good, but he can be signed for that amount. The truth is he didn't get as much hype as he did two seasons ago when they won the Serie A league. In fact, I think what really caused the decline in Osimhen's performances is that their team didn't do better last season. Just imagine if they had done better and finished the season in second position in the Serie A competition; the hype would be more than this, and clubs would be much more interested in Osimhen.
Isn't only tied to the performance of his club Napoli alone, but also tied to his individual performances in both the country and in the club side as well, because during the African Cup of nation , many fans and supporters believed/expected Osimhen to have done incredibly well in that competition and help Nigeria in lifting the trophy, but he performed way far below expectations and couldn't help Nigeria out in the nation's cup competition, I believe that helped drop his rating and market value.
We also do not merely make Osimhen a benchmark for the strength of his country, that this is not just about Osimhen but from the unity of this team, whether they are able to compete or not even though Osimhen did not appear brilliantly to bring Nigeria, of course it is not Osimhen's fault but indeed that their competitors are tougher only compared to Nigeria who only expect Osimhen to perform well of course all players are involved in bad results for Nigeria.
Actually, Osimhen's rent could continue to skyrocket if he is really trained by the right person like Conte, although we do not yet know how far Osimhen will be when trained by Conte next season, whether he will show something positive or otherwise because the competition has not started so we can't just guess or predict, so it's better if we just wait for his proof to become a sharp player or his performance will decline.