He's not worth £100m+, he's was only worth that to premier league clubs and I'm pretty sure they're completely off the table for him. With his baggage, you're probably looking at only Spain or Italy who'll buy him. Good luck ever getting an Italian club to pay more than £30m for him.
So we're left with Spanish clubs and realistically the only ones that could pay that sort of fee are Atleti, Real and Barca. Real will have zero interest in him with their frontline options, so it's basically Barca or Atleti if we want more than £30m.
If Barca were interested, it would have to be creative with players and fees with their levers. Seems unlikely an easy deal would be struck.
Atleti have only paid more than £30m on a player 4 times. Has he really done enough in la liga to warrant that? I don't think so. That's before we get onto the fact that his lack of work rate is not going to be of interest to a manager like Simeone or any manager who expects their forwards to press or defend.
I think Barca would be the most likely option to achieve a transfer more than 30m in value, but it would probably require us buying someone off them. I've not even taken into account what their fan base might think - if there's anyone in this thread that is a Barca fan, they could comment.