My position is that he's currently being paid well under his market value and deserves a pay rise from the same mould that Harry got in the summer.
I genuinely don't get the impression that it's to do with money. I think he would be happy to get the same wage as Kane.
It feels more like satisfying his ambition. If he has the chance to play for four to five years at the likes of Barca / Real, then best of luck to the fella. He's not like Rabiot, who seems to feel he has a God given right to those teams. Rather, he's quietly gone about his business and established himself as one of the best players in World football.
That's obviously pure conjecture and mainly because I love the chap.