How does keeping new players out of the top fighters help?
Unless new players are given a certain amount of perks to spend they will be limited to unperked planes and easy meat. Unless thats what you're looking for?
If you want to keep the better players out of these planes then the only solution I see is a perk system that applies once a player reaches a certain rating or rank.
Ask Shuff,he could care less if he had to pay 20 perks for a D9,he has plenty to spend but chooses to fly a twin engine bomber.....
Now what and how you base the ranking/rating well thats above my pay grade!