At the moment the whole of Egypt is awash with Salah flags and posters in the red of Liverpool. Literally, roads and buildings are awash.
But there have been plenty of comments from fellow players, his family and government leaders that Salah playing for Real is the ultimate goal. For him but mostly for the nation. So much pressure of expectation on his shoulders. So it's a case of when and how much.
One thing is for sure. A player that breaks nearly all PL records is worth three times what Coutinho (that barely broke the 10 goal barrier most seasons) cost. So Perez, 700m you said was it for Asensio?
How can you compare Coutinho's numbers to Salah when they are different types of players? Coutinho had been playing at a high level for atleast a couple of seasons now, which gave him that price tag (along with the fact that Barca had a lot of money in the bag and were desperate to sign him).
A team would be foolish to bid over 100 million for Salah after one great season, no matter how many records he breaks. Plenty of players have gone through similar periods where they look like fantastic players but they can't continue it. Salah is also a huge beneficiary of the Liverpool system, with such a flexible CF who he can rotate position with (similar to Ronaldo at Real), and its not certain if he can recreate those numbers for another team and another set of tactics. He may have to be played as a ST for another team but I don't think he has the complete attributes to play that role.
That being said for Liverpool his value is up in the 200 million, or more. There are very few players in the market, at his age, who I imagine can replace him in the role he plays. Its absolutely vital that they keep him, along with Firmino and Mane, for their long term goals.