Derek Ferguson's interest is in seeing his son get his move, he isn't concerned with how much Aberdeen are paid. Aberdeen care about getting maximum value for the player with Aberdeen fans interests along the same lines as Aberdeen FC. Derek Ferguson has every right to do what he thinks will help his sons interests regardless of what Aberdeen FC or its fans think and he unlike his son isn't an Aberdeen employee and so can do what he likes. You just don't like it because it's against your interests as Aberdeen fans.
It's see through, so stop whining.