Let's be real. PSG are not going to pay 75M for him. Maybe in euros, which is more like 65M pounds? But honestly I'd sell at that price. And there are more than one reason for that.
He's 28 next season. What are his best attributes? Pace, aggression, work rate. His passing, linkup play, crossing, shooting, dribbling are not elite. His vision and football IQ are average. He's the type of players who will fall off a cliff once their physicality is gone. Even more so for these South Americans. At 28 he's not gonna get better technically or physically. If we have to sell this is the best time to milk other clubs.
Then we also have a new manager which seems likely to be Amorim who uses a 343 system. That means Szobo and Elliott will be moved to the forward line and we could lose one of the strikers to make room for a new CB, WB or a CM upgrade. It'd be hard if we are forced to pick one to sell, but if opportunity presents itself like this (the money is good), we should take it.
Of course none of this would make any sense if Amorim comes in and has another idea. But based on the current information selling seems like a sensible option.