wzhmao

My friend lives in an appartment of RWTH studentenwoheim, who has encountered a serious problem now. He lost all the whole key-set including the room key and mailbox key this saturday. Perhaps he has to go to the lost-and-found department of Stadt Aachen and DB next Monday. Has anyone confronted this situation? If he can't find both keys, how much should he pay to get the new keys from house master of Studentenwerk at worst?