In my time using airships I have been noticing a slowly increasing fee to use them. I remember that at the beginning they would cost around 3,200 Gil, but now I am seeing fees of 4,500 Gil.
Is this working as intended? Maybe it is, but why would the airship fares go up? Is it some kind of punishment to finding alternatives to the utterly slow Ferry or not using Anima?

Is the airship fare based on "demand" on the usage or what is it??