Scarce resources, the larger gun especially, a lack of materials for welding (making good welds was almost impossible) and many other factors as everyone above has already pointed out lead to this. Also the lack of transport capacity of the railway system and coal supply did play a role. Constand bombing raids were problems neither the USSR (after their relocation), the UK nor the US encountered on this scale.
Something not mentioned is the price regimes in the Third Reich Economy. Companies were quoted prices in 3 categories, depending on your bookkeeping and accounting system, one or the other was more reasonable. As Henschel might have used different systems than Borsig or whoever, the price of the Tiger II would be different.
Gruppe 1) Tax exempted price
Gruppe 2) Tax deductable price
Gruppe 3) Special offer for extremely difficult and detailed parts
Number 1) regime was usually quite a bit lower than the number 2) regime. As an example take the comparisson and the development of the prices of the BR 52 war locomotive... (It's predecessor, the BR 50, was quoted at 175,000RM in 1939 (Gruppe 1)
Gruppe I - Price without taxed due at the end of the fiscal year H1 42 153,000 RM vs H1 43 150,000 RM
Gruppe II - Price received, but taxed due at the end of the fiscal year H1 42 160,000 RM vs H1 43 155,000 RM
Steam locomotives did not qualify or group III. I will chack back in Tooze's Economy of the Third Reich, maybe he lists tiger II's
If the statistics you are referring to used wrong categories of comparisson, it could add further to discrapancies!
FYI: a great book
https://www.amazon.de/s/?_encoding=UTF8&field-keywords=The%20Wages%20of%20Tyranny.%20The%20Making%20and%20Braking%20of%20the%20Nazi%20Economy&search-alias=english-books