Different asset write-off rules may also make different aircraft more or less attractive to different airlines. I have no idea about the rules for CX vs EK as far as assets go but having so many A380s owned by them is going to make it very hard to sell them all at a decent price when they're done with them. Who is going to buy so many of the things? They have already said that they will return the older ones to the leasing companies when their new order arrives.