Letting go of Victor Osimhen at a low price I don't think Napoli will do that, clubs in Serie A are not like clubs in other leagues which can easily get wealthy investors so they can finance the club well, so one of the ways they get funds to be able to continue to survive in this intense competition is by selling their players who are indeed eyed by many big clubs at high prices, such as Victor Osimhen who has been linked with many big clubs in the English Premier League, Bundesliga and Laliga including PSG who are reportedly interested in him.
Napoli is very likely to keep the price above 120 million euros, because this value will be very useful to finance the club and to buy other players at a cheaper price but the potential is also good. But of course Osimhen's fate will depend on the focus of Napoli wanting to defend the Serie A title, of course he has to defend it because he was one of the keys to Napoli's success last season apart from their old coach Luciano Spalletti who chose to temporarily stop from coaching job.
Their new coach Rudi Garcia does not have good enough statistics in his coaching career if in his first season there is a Napoli player who will leave the club it will be a heavy duty for him at Napoli so losing the Serie A title is very likely Napoli to experience