But if Sane doesn't re-up, we'd lose him in a year. And he'd be worth 35 million in January.
When a player with 1 year left on his contract has decided he isn't staying, it's a bad deal for the parent club. The best you can hope for is a bidding war and a desperate buying club.
Now we wouldn't be inclined to sell him to United, but if we were and Real also showed interest (they haven't) suddenly we've got leverage. But at present the only team we will be willing to see him to showing interest is Bayern.
I'm sure Liverpool and United will pony up the 100 million if we were open to it. But we aren't. That leaves 3 to four clubs - Barca, Bayern, Real, Juve and PSG.