Ironically the high MP cost made it much more expensive than adding a high fuel cost ever could. Ostheer is almost never hurting for fuel, what it does hurt a lot for is MP.
If you priced it as just a more expensive Tiger at a lower CP you would see it far, far more often.
Except it doesnt, Soviets can play with a higher manpower drain and save for an ISU which is priced similarly in MP successfully, so can Ostheer.
The reason its easy to save for a balanced ace is that like Windustry, your tanks start soaking the damage that could go to your infantry which is free compared to loosing members of squads. This alleviation of pressure on your manpower drain means its not nearly has hard to save up while maintaining a field presence.
This is the exact same concept that allows USF to stay competitive in the later stages of the game by no longer getting expensive infantry and spamming tanks instead. Its well known that USF cannot support more than 5 rifles very well, They would die late game trying to keep even more population in infantry.