e.g.. A man goes into a pet shop and goes up to a cage full of parrots'

"How much are your parrots?" he asks the owner.


"Well, he replied, the ones on the floor of the cage are 12/6d; the ones on the middle perch are 15 shillings and the ones on the top are 17/6d".

"Why are the ones on the top dearer?"

"They're on higher perches"

Huh?