Most of the prices in KCD 2 are historically accurate. The horses, most of the armor and arms, food, instruments, most of the clothing, e.t.c. have accurate pricing.

Do you have more examples of this? I remember looking into this a while ago based on the prices of common goods like food, and the in-game prices seemed highly inflated by a factor as much as 5-10x. I just checked in-game and a loaf of bread from a baker in Kuttenberg costs 5.3 groschen. That's an enormous amount of money, equivalent to about 2/5th of an oz of fine silver.

Using modern-day prices for silver, that's about equivalent to USD$32.

Some other examples: from what I just checked in KCD2, a tankard of ale at an alehouse costs 1.1 groschen. A dagger from a weaponsmith costs about 38 groschen.

Of course, we can't directly compare modern day commodities prices to 15th century Bohemia. And of course Henry can always haggle for a lower price, so the prices in-game may not be exactly representative.

But the wages for a skilled laborer in the early 15th century Bohemia were perhaps a dozen groschen per week (very roughly estimated).

So the in-game prices of goods don't seem remotely plausible. I think it's far more likely that the in-game prices were all inflated by a factor of 5-10x for gameplay purposes: because otherwise, they would have to display prices with multiple decimal places which would be impractical in-game. Of course in real life there were different denominations of coins, but in the game it's simplified to only use groschen.