Prior to the BoB CT map, the graduated plane set basically required you to earn your ride.
If I wanted to fly the P-51D, I needed 3 perkies so I upped in P-51B models until I could earn it.
Same with for all late war aircraft. Everything was perked, the SpitIX, La-7, P-47D-25/30's, Dora, G10's, etc. It was a perfect balance in the arena. A majority of early war aircraft was used and other such as the Tempest, Ta-152 ect were moderately priced, including the 262.
It made playing in the CT a lot of fun. MA dweebs and quakers had to tough it out in the older Spit V, Hurricane, Zeke, or the 202/205 until they could earn enough points for their favorite ride.
Personally, I thought it made better pilots of everyone. Your perk ride was costing you so you tended to fly to survive rather than quake around. And it taught the newbies the skills they needed to survive in less superior planes. No longer could you up in NIK2's, SpitIX, or La-7's in endless torrents because it would cost you your perk points.
This brings me to another point. Most Air Forces stick their pilots in older, less powerful aircraft so they respect the aircraft and flying first. Gravy was after they earned it. Imagine if military flight schools started off recruit pilots in F-16's, F-18, Typhoon's to teach basic flight instead of the Hawk or Cessna.
Wouldn't the MA benefit of such a system?