Fact is him and his agent have the power in negotiations. If rumours are true about Torres registration, even more. The only question left is how much Laporta and Alemany want him to stay.
Haaland: 75 games for BVB - 76 goals - 20 assists
Mbappe: 195 games for PSG - 147 goals - 76 assists
Dembele: 126 games for Barca - 30 goals - 23 assists
Now a winger naturally isn't as close to the goal to produce numbers like a 9, but it is a no brainer to stay away from paying Dembele a salary close to what Mbappe and Haaland will ask for. Nice try though, as the people from the club called him better than Mbappe, so it is reasonable from his agent to ask for that. They have power in negotiations, but the club still can stay away from those demands and not give in. Extending his contract would be strategically smart for various reasons, but there are boundaries...