Regarding the high cost of buildings... the building for behemoths is cheap. For any other faction, buildings for level 7 creatures cost at least 14k.
Maybe make a specialized resource on the warehouse – gold? For example, plus 500. If you want to differentiate it from the academy, you can add 1k. Then the high price of other buildings will be justified. Although, to be honest, in the dungeon, they can be even more expensive. It seems so.
I suggested calling the building for monsters a haven, residence, or prison (Ar, not what you thought, xd) of something. I remember we never decided.
Since you are busy developing buildings, I will probably come up with some abilities for the Nighon school in my spare time. But I think it will turn out to be something like a three-level gnome or orc guild. Unless we introduce another school of magic. Although... an idea has just occurred to me. But I will only express it in ICQ, because heretics and plagiarists are everywhere.
P.S. Ar, you will have to come to terms with it) Mighty me is here^_^ bugoga ;D
P.P.S. Let's say – you will learn to love marmalade) of something