Could be a tactic to get them to accept bonus formula. PSG maby offered 75 million euros upfront. If we offered 65+ 10 in bonus they could easily say we want 75 million euros upfront.
Now we are making them nervous with a bid smaller then PSG. So when we reach 75 million euros or close to it, they will accept it, even with bonuses. 63 million euros + 8-10 in bonus . Just a theory