Heroes 5.5 WarGame Edition - Tactical Edition.

Economic balance (know-how):

Resource Acquisition Value = Resource Expenditure Value * Resource Variability^1/3

Resource Expenditure Value = Base Resource Value * Resource Scarcity

Resource Variability = Resource Demand / Gold Demand

Resource Scarcity = Resource Demand / Resource Supply

Resource Demand = Resource Need / Sum (Need of All Resources)

Resource Need = Base Value * Required Resource Quantity (for all expenses: building a city, buying troops, heroes, war machines)

Resource Supply = Resource Production / Sum (Production of All Resources)

Resource Production = Base Resource Value * Resource Quantity on the Map

Base Resource Value - is set arbitrarily as a kind of standard, in gold (example: 1 rare resource = 500 gold, 1 common resource = 250 gold).

Comments:
The degree applied to Variability is determined based on the following considerations: for 8 ways of using a resource, a multiplier of x2 is offered to the value, compared to 1 way.

Examples:

Let there be 70 piles of gold of 500, and 5 piles of resources of 1 rare or 2 common. Then:

Gold Production = 500 * 70 = 35000
Rare Resource Production = 500 * 5 = 2500, total 10000 for 4 rare
Common Resource Production = 250 * 2 * 5 = 2500, total 5000 for 2 common
Total Resource Production = 35000 + 10000 + 5000 = 50000

Gold Supply = 35000 / 50000 = 70%
Resource Supply = 2500 / 50000 = 5% for each of the other resources

Let's assume that the construction and purchase require as many resources as there are on the map (or proportionally). Then:

Gold Demand = 70%
Resource Demand = 5% for each of the other resources

Resource Scarcity = 1 in this case (a completely balanced map and city composition, without bias)
Resource Expenditure Value = Base Resource Value in this case, i.e. 500 for rare and 250 for common resources.

Resource Variability = 5% / 70% = 1/14, i.e. gold is relevant 14 times more often than any of the resources.
Accordingly, the Resource Acquisition Value decreases by approximately 2.4 times to 200 for rare and 100 for common resources.

How this will work for cities:
The Resource Expenditure Value will be taken into account, depending on the Scarcity. If, for example, a city requires twice as much Mercury as Crystals for construction (with an equal supply from the map), then this means that each Mercury has twice the value of a Crystal.
Which is logical: it is clear that for Necropolis, the consumption of each unit of Mercury is critical, unlike Crystals. And if Mercury is replaced with Crystal in the same amount in any of the buildings, then this will actually be a cheaper building.
But even more importantly, the value of obtaining Mercury for Necropolis will increase even more, by 2.5 times (more can be bought for this resource + this resource is required more often).