If osimhen's price is continue to drop, then club will be caring about that. 
In the end, buying lukaku from chelsea is not a bad option, and im sure this can be an opportunity to push osimthen to give more.
Osimhen should be retained instead of selling him at a cheap price, especially if his price decreases because his performance may also appear to have decreased playing with Napoli last season which didn't perform well, although Lukaku, if he can be bought, should be able to partner with Osimhen, it's not bad enough, he might even be able to make a game. can be more interesting and provide color for Napoli next season, Conte should be able to find an alternative for Osimhen, this can at least make him improve his game even better and make his performance also increase and not continue to decline so that it can make his value continue to fall. In the end, buying lukaku from chelsea is not a bad option, and im sure this can be an opportunity to push osimthen to give more. Napoli could buy Lukaku and keep Oshimen but they are both strikers of course they cannot be played at the same time while Napoli also still has Khvicha Kvaratskhelia who helps Oshimen on the front line so Napoli cannot put them in the same position and give up one of them.
But I am also very curious about Conte's strategy in honing Oshimen's skills and I also want to see the coach use his best players. According to rumors circulating, Conte actually wants to keep Oshimen but the management wants to sell him.