This whole discussion (especially Panther related stuff) keeps ignoring that one of the main factors that drives tank price is actually armor and HP. The Panther is that expensive because Allied mediums are super unreliable in frontally penetrating it. Also it can take 6 hits insted of 4. The Pen of the Panther is decent, but not needed unless the Allies player calls in a heavy tank. If you just want a next to 100% penetration chance against basically all Allied stock vehicles (and many call ins, too), a StuG would do. What the StuG does not provide is a turret and high survivability ("only" 140 armor and 4 hits worth of HP).
Just comparing raw pen values is pretty much stupid by itself, because it tells you nothing. You need to calculate pen chances against certain targets, but that apparently is too much effort for many of our forum keyboard warriors.
With that said, back to a hopefully more normal discussion.
and you are ignoring rate of fire and gun's arcs as well as how durable their crew is. Pak is only marginally better (which means almost nothing in a real game scenario - 10 more penetration - ridiculous), while othe at guns have wider arcs of fire and often higher rate of fire.
Aren't arcs standardized the exception of Raketenwerfer?
But AT guns are now all pretty close (exception 57mm, which has way lower pen and higher ROF). The ZiS3 has 6 men, but also slower rate of fire. 6-pounder and PaK40 are almost carbon copies, Raketenwerfer has now been more standardized with the range buff, the main differences here are retreat functionality that compensates the lower survivability due to lacking shield and model spacing.
Axis AT guns can basically penetrate all Allied stock units, the limiting factor is hit chance. For Zis and 6Pounder it is the same with the exception of the heaviest Axis tier (Panther, Bummbär and OKW P4). The 57mm even starts to struggle against mediums.
and again the differences are too tiny to be significant. Rate of fire, speed, turret riotation will be more important here. Again the price of p4 might not be justified here, the price of a panther might also be just too high.
As I said, please factor in the armor of the opponent. Against other mediums, the P4 wins at long distances. At short distances (5m), Allied tanks EVEN OUT their penetration chance (almost at least) with every tank having ~75% pen chance against each other. Raw pen values are misleading. Also, the P4 has a very slight edge in ROF, Sherman in moving acc, Cromwell has a bit higher top speed.
I'd say the P4 is fine. Panther is more difficult to compare since there is no direct Allied counterpart. One thing that gets ignored though in the Panther vs Allied TD discussions is that the Panther is way tankier (4 vs 6 hits) for costing about 90MP/45FU (+22,5%/+32,1% over Jackson) more. Now you don't get the additional firepower etc, but for getting 50% more HP and also better armor while similar mobility it's not bad. The main drawback of the Panther is the 10 range difference compared to Allied TDs, which - given the rest of Panthers stats - they also need to be able to deal with a Panther if microed correctly.