I've seen a number of figures thrown around, including a free transfer if Arsenal just takes his wages off Bayern's books. In any case, if Arsenal isn't going to allow them to run out their contracts, Sokratis and Mustafi will both be moved in the summer. Mavropanos needs to be sent out on loan or sold. So Saliba, Boateng and a new signing could replace Sokratis, Mustafi and Mavropanos. That's three in, three out.