In my opinion, Osimhen will relatively stay with Napoli because so far no team is really serious about signing him other than just saying they are interested. Napoli will have to keep their star players with them for next season if they want to strengthen themselves as the strongest team in Serie A next season.
To be honest If osimhen wants to chase money then he joins Saudi Arabia league Team in this Transfer market. I think that Osimhen will not do this because given his young age, of course he wants to win many trophies in prestigious leagues in Europe. Apart from that, the big European teams that are able to bring in Osimhen are most likely Real Madrid and PSG.
It is true that so far only a few teams are interested but no official offers have come in for Victor Osimhen yet. I think if Napoli wants to keep one of the key players it is with a contract renewal and an increase in weekly wages. At least that can make Victor Osimhen more comfortable at Napoli and if there is an offer from another club he can later turn it down for that reason. However, if we look at the current situation, everything can happen so quickly and indeed PSG or Real Madrid are strong candidates for teams that will start bidding for Victor Osimhen considering that the position for the main striker is still vacant until now.