I know what you mean, I always buy the team shirts directly from Chelsea because I want to make sure they get as much of the money as possible. I dont know if it helps or works out that way though
He is worth around 50m imo. He is already worldclass and he has a lot of years to give and should even improve a lot. I would love him here even though we were to pay a lot to get him.
I dont like that Courtois gives rebounds in front of the goal either. He should improve in that area and punch the ball to the side and not in front of the goal. He does it all the time as I see it.
Cech is still young for a GK, and he is a solid worldclass keeper. At the same time he has a lot of experience from the PL which Courtois doesnt have. I dont know if it's a good idea to just sell Cech tbh.