I think the perk price is about balance. By some what limiting but not completely stopping the use of some of the equipment it gives players 1, something to work for, and 2 a bit of variety in what they run into. The Chog is the one that started it. When it first came out it was THE ride of choice. The hog in it self is a great plane, add it the best fire power in the game and its a monster! So everyone used it and that was all you pretty much saw, well those and Ak-AKs 38
The GVs came later in the development of the game and I think maybe HTC added the same perk prices to hepl control the the balance a bit better. It may be a bit of a nightmare to rebuild the perks system of the older stuff (planes), or it just may not be that high on the list of things to do, but it has been a long time since the last adjustment to the perks on planes. Lusche? You can chime in here, was it a 190 that got changed?
Another thought, it IS Aces High after all and maybe they have less planes perked because they would like to see players in planes.