Teching costs
T70: 95/105
Sherman 170/180
King Tiger 195 (without caches)
IS-2: CP only
Unit costs:
T70: 70
Sherman: 110
King Tiger 280 (without caches)
Thus the question to be asked is by the time anyone accumulates cc. 500 fuel (OKW can't build caches), is it one King Tiger or cc 3 Shermans firing HE is the one that decrews ATGs faster and more reliably.
It is also a question of which fires at 4 men Squads and Weapons teams the most and which one fires on 5-6 men squads and weapon teams.
I dont think any cost justify the power of the King Tiger. Maybe in 1 vs 1 its ok but in 2vs2+ you realy get problems. The Problem lies more within its durability + its damge it can inflict on Infantery. One SU-85 can barely push it away so you need 2 and even than you cant kill it reliable. So you need to pay 260 fuel on only AT to fear it certainly away.
The King Tiger on the otherhand can push forward fire a round killing half of a squad and retreat to save after.
In higher gamemodes if you dont lose hard in early or mid game you can easely save for the KT. Than mix in a Jagdtiger or an Elephant to counter all the AT vehicles and a Stuka zu Fuß for the AT-Guns and you get a hard to counter Combo.
I admit the KT is very expensive but nevertheless its to good against everything. It got 45 Range and 240 damage with goiod penetration. So exept for the Comet, the Pershing (even Range) and all AT-Vehicles it outranges the most Tanks. So its not a teribble AT-Unit. And beside of this its so deadly against Infantery.
I think its very cost efficient for what it does. But even if the cost effiency isnt given, the King Tiger does have a to big impact. So my suggestion is to nerf its performance against Infantery. Its forgiveness is kind of adressed in the DBP by nerfing the repair spead. But in exchange if its to UP reduce its price.