The Ta152H-1 or the F4U-4 would be justified in some amount of perkage as to retain its status as a 'rare' fighter to see in WW2. More or less same logic can apply to the Tempest V.
However the Spit14 is not.
The Spit14 was a common fighter and a regular addition to the RAF which could be seen in large numbers since 1944. It's performance as a fighter is impressive, but not so high as to justify the current, penalizingly high prices.
Like some have already mentioned, it's low-altitude speed range is still slower than quite a large number of planes.
It boasts excellent climbing ablities and acceleration, but the Bf109G-10 is readily on par with the Spit14, which is a free plane.
It has excellent maneuverabilty for a plane of its speed, but again, this is not a trait which only the Spit14 has.
It's high alt performance is very good, but still a lot of plane are as fast(or even faster, such as the Bf109G-10 marked at 452mph at 22k), and also boast much simular high alt qualities.
All in all, the arena is already full of late-war variants such as the La-7, P-51D, Fw190D-9, Bf109G-10, and etc etc., but of those many planes of many nationalities only the RAF is exmept from being able to use a competitive late-war plane for free.
I know how much you hate people assuming they know what you think, but in this case there's honestly no reason I can think of why the Spit14 must remain at such a high price range.
What I can think of, is that the Spit14 was always a 'controversial' plane in terms of overuse, and subject to so many cynicism from all kinds of games before AH - WB, AW, FA.. etc etc.... and I am guessing that these past experiences influenced your decision about its status - whether to be perked or not, and how high it must be perked, if it is decided so... But I must cautiously protest that this might be an overkill.
The Spit14 started out as a perked plane, unlike the F4U-1C which started as a non-perked plane.
HTC went through a grueling process of evaluating its overuse, and finally arrived at its current price which has successfully limited its overall numbers, but not making it a totally rare plane, and fairly accessible at low prices.
Contrary to that, the Spit14 started off as a perked plane from the beginning of its introduction. To my knowledge, so far such planes which were perked from the start were always very high in performance that it was almost self-explanatory - like the 163 and 262, or even the Tempest V. Most people won't have to think "why was this plane perked from the start?"
However, I believe that the Spit14 is different, as explained in the beginning of the post. The only distinct qualities it has over other planes, is that it is a plane balanced in speed and maneuverability, which is a rare trait. Indeed, such a trait is a reason for popularity, as we can see in the example of the Spit9 or the N1K2. However, that reason alone cannot explain such penalizingly high prices for such a significant plane of WW2.
So I humbly plead, please, how about a test-period for the Spit14 for about two tours? If it is really so dangerous as to be needed to be perked at such high ranges, then it can always become re-perked.
In my personal thought, the Spit14, even if it is perked, won't be of any threat to the MA in terms of balance. If it stays anywhere around 8~10%(in kills), I would expect it to be tolerable levels(as the La-7 and the P-51D have all maintained such high usage rate since the beginning of their introduction).
If it would surge higher than 10%, then it would need to be perked, which should be adequate at 5~8 points tops, to successfully limit its usage. Previously, we saw a plane with 20% usage drop down to 2~3% levels with just 8 perks, in the example of the F4U-1C.
If the Spit14 is in the 50 point price range from the beginning, then it must mean that HTC does not think it's just another plane that is plainly overused, but a plane with very high performance that needs to be suppressed with perks, to contain its usage. And that, is what I am very skeptical of.
Please, just for two~three tours, try the Spitfire Mk.XIV as a free plane... and then, evaluate its perk price according to usage!
Thanks for listening.