Yes, he will probably refrain. You are thinking of this one purchase, he is thinking about his business in the next years/decades. He has already compromised with you, maybe there is still some room. But anything over 50% would be a real surprise.
PS: I am the last person who would say that the broker honestly earned 18k with his "work," but that's just how it goes – at least for now, as long as the costs can simply be passed on to the buyer.