Posts from AnotherGame is a mod for ToE 3.1. Auto-translated

Cost - 1 week + . Doubles the resource gain rate.
Actually, for Heroes of Might and Magic, that's still not enough...

I especially agree with Nargott regarding revenge; it's already been nerfed in 3.1, so why nerf it further? Besides, there are more overpowered spells, like Fan.

I understand, in Heroes of Might and Magic, most maps have incredibly rich resources due to the huge number of treasure chests. If mines also give double the income...

In any normal tournament, without new versions of the game, the Tower faction was banned!

1000-2000? Heh. No one is forcing you to upgrade all mines.
Although, I was thinking of making it 5000 + 5 stone and 5 wood, but that's not quite right...
The price was not chosen randomly and was based on the lowest prices on the market + self-sufficiency.

Yes, it was surprising. Apparently, they are introducing absurd restrictions even in tournaments. You'd think that winning a game is possible thanks to a tower, by forcing the opponent to attack with fewer forces and without scouting.

What are the prices on the market? The cost of 1 resource is 100 gold, and a rare resource is 200 gold. This is a perfectly natural rate.

However, if you look at it through the lens of the exorbitant market prices, where only 1 rare resource is offered for 5,000 gold, your approach is appropriate. From a market perspective - because no one will use this method to inject resources that are not in short supply (I practically never exchanged gold for resources, only surplus resources).

The market itself is primarily a tool for selling surplus resources. It is not economically beneficial at all, and trade is used only in emergencies or for resources that are essentially useless. It turns out that you have the same approach to developing mines – only in emergencies (I can't imagine when there would be a surplus of gold). But again, if you compare it to a warehouse, the upgrade price should be adjusted accordingly.

So, if we follow a purely market-based approach, the price would be around 35,000. I get a fifth of that. But the payback period shouldn't be longer than a week, and the upgrade costs should be the same for everyone. In terms of gold, that's 7,001 gold. But the number isn't very appealing, so I increased it to 7,500. However, in the end, the market only adjusted the cost of mines by 2,500, not 30,000 :) +
Maybe we can analyze it with a specific example?
Necromancer? Elf? Would it be profitable for an Elf to upgrade a lumber mill?

No, no. The market approach cannot be applied in the same way to income. Because a shortage of 1-3 resources is usually discovered on the same day they are needed. The point of the market is that you can exchange any amount of resources at once.
In your case (mines), this is not the case. Therefore, it is more logical to apply the warehouse approach.
As for gold, its payback period is 5 days (like the Capitol branch), since there is no exchange here.

Simple math. The cost of a rare resource is 200, and it can be exchanged on the market for 5000 gold. That's a 25-fold difference. But you can exchange any resource for any other. In the case of mines, you can't exchange just any resource for any other; it's mostly gold for any other. It would then make sense to have a 5-fold difference (the square root of 25) for a halving of the freedom of choice. But then we also get an equivalent income of 1000 per day, and a payback period of 5 days = 5000.

Let's analyze it using the Elf example. 5000 is the maximum price that I personally am willing to pay for a shortage of wood. The same applies to mercury for the Undead. The Warehouse is slightly more expensive (+5 stone), but its advantage is that it can be built at any time, including at the beginning of the game, and not only when the mercury mine has already been captured (and development only speeds up the growth).

The Capitol is a unique structure. The mine should not disrupt the principle of a unique structure, and its profitability should already be higher.

Even comparing it to a magistrate is not worth it, because it adds the possibility of additional upgrades.

Besides, the player should have common sense that it would be unprofitable for him to upgrade all the mines, and upgrading most of the mines may be affordable at a low price....

Well, with the Undead, I meant stone, but never mind.

I said - BRANCH of the capitol. That is, the magistrate, the town hall, and...

You yourself can see that the market is almost always available. This means there are no problems with warehouse availability. What will I choose: build a warehouse for 5000 and 5 stone, or upgrade a specialized mine for 7500, which can also be easily captured?

The Castle takes 20 days to build. This is an increase of 40 stacks of wood.
Is it worth paying such a price for 7500?

Perhaps there is only one such branch for a single player game. What difference does it make? The essence won't change.

You would build a warehouse much later than you capture the necessary mine anyway.
And how will you build a wood warehouse?

The Castle takes 20 days to build. That's an increase of 40 stacks of wood.
Is it worth paying such a price for 7500?

The difference is significant. Should I build a town hall for 5000, which provides a +1000 bonus to gold, or upgrade a gold mine for 7500?

I don't understand the point; what does the castle's construction time and the mine's output have to do with it? I'll only get 40 stacks of wood by the end of the period. Be consistent with the payback period – 7 days means 7 days, not 20.
In the case of the Elves (and I would never trade 7500 gold for 40 wood for other races), a lot of wood is only needed in the first week.

I'll say it again: there's no difference in how uniqueness is defined.

So, the other 20 units of wood are just for nothing?