How to make money as Ogre Kingdoms

Ogre Kingdoms's fastest-paying building in Total War: Warhammer III is the Raft Jetty (Port, level 1): 1,000 gold for +250 gold a turn, its cost back in 4 turns once built. The most gold from one building slot is the Big Gem Mine at +600 a turn (6,000 gold to build the chain that far, back in 10 turns). 23 Ogre Kingdoms building levels make flat income, patch 9.0.4.

Fastest payback

Turns of income to earn the building's cost back (each chain's fastest level).

1Raft JettyPort 1 · 1,000 gold → +250 a turn · Port settlement4turns
2Big Gem MineGem Mining 3 · 3,000 gold → +600 a turn · Region with the resource5turns
3MintGold Mining 3 · 3,000 gold → +600 a turn · Region with the resource5turns
4Gold HoardIncome 1 · 750 gold → +150 a turn · Any settlement5turns
5Animal StoreTusks 1 · 1,000 gold → +150 a turn · Region with the resource6.7turns
6OrchardsOrchards 1 · 1,000 gold → +150 a turn · Region with the resource6.7turns

Most gold per building slot

Income of each chain's top level; the line shows that level's own cost.

1Big Gem MineGem Mining 3 · 3,000 gold → +600 a turn · Region with the resource+600a turn
2MintGold Mining 3 · 3,000 gold → +600 a turn · Region with the resource+600a turn
3Big WharfPort 2 · 3,000 gold → +500 a turn · Port settlement+500a turn
4Eastern BazaarSpice Trading 3 · 3,000 gold → +400 a turn · Region with the resource+400a turn
5Marble WerksMarble Quarry 3 · 3,000 gold → +400 a turn · Region with the resource+400a turn
6Tusk CompoundTusks 3 · 3,000 gold → +400 a turn · Region with the resource+400a turn

COMPUTEDIncome = the level's flat gold per turn (the game's “Income generated” effects on the building itself, table building_effects_junction) minus its upkeep (building_levels.upkeep_cost). Payback = cost (create_cost) ÷ income. Upgrade payback = the level's cost ÷ the income it adds over the level below. “Gold back by turn” = build turns (create_time) + payback, counted from the order. Chain total = every level's cost up to this one, and its payback = that total ÷ income. Patch 9.0.4.

ASSUMPTIONS

Base values: technologies, lord skills, commandments, campaign difficulty and faction effects that change income or building costs are not counted.
Percentage boosts (“+4% income from all buildings in the province”, “+20% (local region)”) are not in the payback: they depend on the buildings they boost. They are listed below with the income those buildings need to make.
Conditional income (“When Control is 75 or more”, “When enemy Lord is present”…) is not counted; listed below in the game's words.
Resource buildings need a region with that resource; ports need a port settlement. A slot can hold one building, so late in a campaign gold per slot matters more than payback.

Every Ogre Kingdoms building that makes gold (23)

#
1	Raft Jetty	Port	1	1,000	2	250	4	—	6	Port settlement
2	Gold Hoard	Income	1	750	1	150	5	—	6	Any settlement
3	Gem Mineshaft	Gem Mining	1	1,000	1	200	5	—	6	Region with the resource
4	Gem Mine	Gem Mining	2	2,000	2	400	5	10	7	Region with the resource
5	Big Gem Mine	Gem Mining	3	3,000	4	600	5	15	9	Region with the resource
6	Gold Mining Pit	Gold Mining	1	1,000	1	200	5	—	6	Region with the resource
7	Gold Mine	Gold Mining	2	2,000	2	400	5	10	7	Region with the resource
8	Mint	Gold Mining	3	3,000	4	600	5	15	9	Region with the resource
9	Big Wharf	Port	2	3,000	4	500	6	12	10	Port settlement
10	Animal Store	Tusks	1	1,000	1	150	6.70	—	7.70	Region with the resource
11	Quarry	Marble Quarry	1	1,000	1	150	6.70	—	7.70	Region with the resource
12	Spice Market	Spice Trading	1	1,000	1	150	6.70	—	7.70	Region with the resource
13	Orchards	Orchards	1	1,000	1	150	6.70	—	7.70	Region with the resource
14	Tusk Compound	Tusks	3	3,000	4	400	7.50	20	11.50	Region with the resource
15	Marble Werks	Marble Quarry	3	3,000	4	400	7.50	20	11.50	Region with the resource
16	Eastern Bazaar	Spice Trading	3	3,000	4	400	7.50	20	11.50	Region with the resource
17	Vintner	Orchards	3	3,000	4	400	7.50	20	11.50	Region with the resource
18	Paychest Store	Income	2	2,000	2	250	8	20	10	Any settlement
19	Tusk Market	Tusks	2	2,000	2	250	8	20	10	Region with the resource
20	Granite Werks	Marble Quarry	2	2,000	2	250	8	20	10	Region with the resource
21	Spice Trading Post	Spice Trading	2	2,000	2	250	8	20	10	Region with the resource
22	Vineyard	Orchards	2	2,000	2	250	8	20	10	Region with the resource
23	Counting House	Income	3	4,000	4	400	10	26.70	14	Any settlement

Main building levels

Settlement upgrades make gold too, but they also cost growth (population surplus) and open building slots, so payback alone undersells them. Province capitals and minor settlements are separate chains.

#
1	Stew Kitch'n	Major Settlement	1	1,500	—	50	—
2	Stew Kitch'n	Minor Settlement	1	1,500	—	50	—
3	Maw Cave	Major Settlement	2	2,500	1	75	100
4	Maw Cave	Minor Settlement	2	2,500	1	75	100
5	Cauldron Town	Major Settlement	3	5,000	2	150	66.70
6	Cauldron Town	Minor Settlement	3	5,000	2	100	200

Every level's full effects: Ogre Kingdoms buildings.