The Panther was widely considered UP after it's double nerf last year (cost increase 145 -> 175, less armour & health).
The job of a panther is to destroy tanks and it does so at a premium cost.
OP is delusional to claim it's "too cheap" for what it does without providing any calculations. I hate when people use words like "price efficiency" , without providing any formulas or calculations, basically trying to lift their subjective feelings into a scientific sphere.
Also, funny to see how OP fails to mention that panther has less DPS than an SU 85 & Jackson (about 60-70 % of those, watch here for comparison
1 2 3) Hence it's balanced around being able to take more, but also only able to deal less.
I like a balanced game, but I absolutely hate if units get nerfed so hard that they don't get used anymore. It was this case with the panther and I guess OP is just a new player and therefore doesn't know the old days.
Another indicator that shows the panther is fine: It's not a no brainer and the must choice for every game, like it was back then with 100 range ISU. Basically every game ISU vs Elefant.
Also OP I suggest you stop hiding your playercard since you post a lot of these kinds of this threads without providing any authority.