Napoli definitely got what they wanted in this transfer. They found a team willing to pay him the price for a player whose contract is about to expire. I think it's a risky transfer for Galatasaray, because no transfer fee has been paid in Turkey that's even close to this. Being Turkish, I know the team's financial situation will be investigated. This represents a financial burden that could cause difficulties for Galatasaray. For Napoli, everything is going well. If Galatasaray doesn't achieve success in Europe next year, then this transfer will be a major problem for them, as no European team will be able to pay him more than 75 million.
Napoli in many years with De Launrentis management have shown that they are very clever in transfer market and this transfer of Osimhen to Gatasaray is another example. They no longer need Osimhen and they won a Scudetto last season without him as well as without Kvaratskhelia in a second half of season. Letting Osimhem moving to Galatasaray and getting good money for transfer and salary budget is a very good deal for Napoli.
They will be able to build up a better squad with money from the Osimhen transfer and can continue to maintain their position in top four of Serie A. It's hard to defend Scudetto or win it too often but appearing in top four of Serie A in every season will be good achievement for Napoli.