he ain't gonna get 5m€ anywhere else than maybe from EPL mid-table side.
I don't know where this comes from, but PL mid-table sides do not pay anywhere near those kind of contracts. They have probably only one player that makes something like 3m and he's usually a player they're expecting to sell in the near future, or some leader for years to come. What they have is the luxury to pay a lot of (usually junk) players decent money that is star money for bottom half Serie A or La Liga clubs.
Everton iirc has a lot of players on 2-2.5m deals, but I think only Richarlison exceeds that and it's not much more than 3m annually. Teams like West Ham, Leicester, Wolves and perhaps Leeds have the luxury to have 2 players above 3m, but not very often above 3.5m. Several clubs do not pay more than 2m either. That's because those players should be getting paid at best 1.5m per annum but happily accept a PL contract as it inflates their wallets. Getting a 500k or 1m premium is too much to ignore for some of these guys who can consider themselves lucky to be sought after by top tier teams of any top 8 league.
If Perisic wants 5m and a starting spot in England, he can only find that at Arsenal. I don't think he'd like that very much.