I really dont know what you're on about. We're only having this discussion in the first place because Higuain has a release clause. Simple. Our relationship with them doesnt matter as long as we trigger the clause.
PSG are a top European team, yes. 500M revenues, star players and winning league titles. Compare them to Napoli, its an apples to oranges comparison. They dont want to let go off Cavani. When Barca for example wanted to sign Marquinhos, they threatened them of triggering Messi's release clause. Thats how strong and wealthy they are. If they want to keep their players, we have no chance at signing any of them.
So yes higuain deal is much easier than Cavani because Higuain has a release clause regardless of the numbers being mentioned. Next thing you're gonna tell me 'Signing Verratti is an easy deal' or what ?!