i doubt if Arsenal was willing to pay that much for Osimhen, they are known to be a team that can’t pay much for players.
Gunners are without a top striker this season, converting Kai Havertz to play in the nine position was good enough for Mikel Arteta but not fully comprehended for the team's pattern of play. Gunners urge to buy more attackers in the frontline. Victor Osimhen would definitely fit into the perfect picture of every elite club, there are passive means of enabling the striker playing for EPL side but Napoli was strictly based on the fee which other parties didn't agree. Arsenal is elite club that are not willing to pay such huge amount for a player, the team's management structure is diverse based on specified amount ought to spend on players.
Under Arteta's command, Arsenal has shown solid strength and as a club that is favored to be a strong candidate for the EPL champion this season and a tough competitor in European competitions. It only takes a little more polish for Arteta to perfect his squad, bringing Osimhen to the Emirates Stadium is the main choice because as you said, Arsenal currently needs a strong striker and that place is suitable for Osimhen. If the plan really happens, I imagine the duet of Osimhen and Kai Havertz in the future, how fierce Arsenal will be at that time. Talking about the price, Arsenal management should try if Arteta really wants this player.
They should pay a very high transfer fee for Osimhen. Osimhen will play on loan at Galatasaray until January. Napoli extended his contract until 2027. So there is no chance of him leaving for free at the end of the year. He is a player who can adapt to the Premier League and I think he will be a great advantage for Arsenal. I think Arteta should bring him to the team and use him in the best way. The Premier League championship can come this year.