180 million is indeed too much for Osimhen. Mbappe was signed for that amount by PSG. 
Of course the conditions of that time and now aren't the same. Players are getting more expensive in the transfer market now that we see even average level players being signed for really high amount of money. But I still don't think 180 million can be given just like that to any player. Osimhen is a really talented striker undoubtedly. But is he really worth the risk of paying a huge amount?
I don't think he is worth it now. He is still young and he needs to improve continually to prove his worth.
Of course the conditions of that time and now aren't the same. Players are getting more expensive in the transfer market now that we see even average level players being signed for really high amount of money. But I still don't think 180 million can be given just like that to any player. Osimhen is a really talented striker undoubtedly. But is he really worth the risk of paying a huge amount?I don't think he is worth it now. He is still young and he needs to improve continually to prove his worth.
If his current market value and money placed on him by Napoli is compared to Mbappe market value then it’s probably worth it. But to end all of this, Napoli don’t want to let him go now that’s way a big price like this his placed on him. He happens to be the third most valuable striker in the world now but the consistency is what matters now to any team that is willing to have him by their side. No team will want to pay such huge amount and later not get what they deserve. There’s very high possibility that he’s going to remain at Napoli and this won’t be a bad decision for him to stay back.