One other factor that will come up for you in later game is that the trader calculates unurium production based on working population (base production) and required culture (collection bonus). So, if you get most of your goods from wholesaler trades (fewer manufacturies) and your population from event buildings (versus residences), you are going to generate less unurium. Of course, there are A LOT of chapters before that becomes an issue, and it is not impossible to overcome, just something for which to plan.
I could never purchase enough goods to cover my weekly catering costs - and I have a hybrid city - without factories, because the amount of goods that can be purchased from the wholesaler is capped by supply capacity. I think the maximum number of purchases possible is 114 for supplies & 114 for Coins. However, 14 purchases would cost me 450,420,000 supplies, and I could not meet the demand without adding many more Magic Workshops and if I had standard workshops, and no matter how high my culture bonus - I do not think it is possible to house the number of Workshops, the residences for the pop, and the culture for both - within my city.
So, there is the built in cap relative to city supply & coin capacity and a cap relative to the cities coin & supply production. However, a catering city that limits themselves to 15 to 20 tournament provinces - weekly - might be able to purchase enough goods to cover the catering costs with wholesale purchases - eliminating the need for factories. A city that only plays enough to earn 1600 points to cover their portion of a ten-chest fellowship - only requires 6 rounds of 6 provinces - the cost to cater or use troops is so low it is a wonder that any player with 6 available provinces does not earn the 1600 points.
For me and my hybrid - I typically complete - Rounds 1 & 2 (40 to 45) - Rounds 3 & 4 (35 to 40) Rounds 5 & 6 (25 to 30)
So, demand is basically the amount of Spire & Tournament a player participates - the more you play the more you pay
I was thinking this morning and it occurred to me a hybrid city that plays a lot of tournament & spire - will have a higher catering expense catering 20 provinces of all 6 rounds than a catering city, because - at least for me - my catering begins when troop effectiveness & availability ends - so to negotiate 20 provinces beginning at number 20 is far more expensive than the 1st 20 provinces. So, considering both when the catering begins & the number of rounds the difference in resource cost is substantially higher.
However, to negotiate 40 provinces of 6 rounds the resource cost is obscene, and I know this because a while back I completed the same amount as my typical through negotiation and my standard goods alone cost over 23,000,000.
I could not afford to play the amount of tournament I do through catering alone.
This is the amount of standard goods my city produces in 7 days with
28 wholesale purchases per tier daily
4 - level 31 Marble, 8 Level 27 Silk, & 4 level 27 Gem
My Bell, Building Sets, & Evolves
7 Day Total - T1: 9,741,872
7 Day Total - T2: 7,167,538
7 Day Total - T3: 4,956,980
I could also never play my typical with my troops alone - not even with my fire & troop boost temps
These are all of my Ancient Wonders - I keep this list to anticipate research cost and track my swaps - so ignore the kp
1 - Golden Abyss - Level 26 - 780 kp
2 - Needles of Tempest - Level 21 - 835 kp
3 - Sanctuary - Level 17 - 980 kp
4 - The Great Bell Spire - Level 24 - 1160 kp
5 - Watchtower Ruins - Level 22 - 1010 kp
6 - Dwarven Bulwark - Level 15 - Rune Stage
7 - Mountain Halls - Level 16 - 920 kp
8 - Prosperity Towers - Level 23 - 1040 kp
9 - Blooming Trader Guild - Level 21 - 930 kp
10 - Heroes' Forge - Level 16 - 940 kp
11 - Shrine of Shrewdy - Level 16 - 830 kp
12 - Enar's Embassy - Level 13 - 174 kp
13 - Flying Academy - Level 21 - 870 kp
14 - Maze of Dark Matter - Level 16 - 1060 kp
15 - Dragon Abbey - Level 17 - 860 kp
16 - Temple of Toads - Level 17 - 810 kp
17 - Elvenar Trade Center - level 17 - 980 kp
18 - Sunset Towers - Level 17 - 880 kp
19 - Victory Springs - level 16 - 920 kp
20 - Pyramid of Purification - Level 16 - 920 kp
21 - Lighthouse of Good Neighborhood - Level 23 - 1160 kp
22 - Time Warp - Level 17 - 810 kp
23 - Simia Sapins - Level 16 - 1060 kp
24 - Vortex of Storage - Level 8 - 700 kp
25 - Thermal Spring of Youth - Level 8 -700 kp
This is my Current Resource & Troop availability - after the 1st round of the Tournament & negotiating the gateway & high Halls.
My Standard Goods production & my current inventory - tells the tale of my catering costs.
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My city
8 - Chapter 16 Magic Workshops
18 - Chapter 16 Magic Residences
4 - level 31 Marble Factories
8 - Level 27 Silk Factories
4 - Level 27 Gem Factories
3 - Level 35 Armories
Level 37 Barracks
Level 24 Training Grounds
Level 20 Mercenary
Level 35 Main Hall
And all of these buildings benefit from my 25 Ancient Wonders.
This is what my expenses demand of my city - and what I have built to pay the cost.
My goal is to increase my tournament participation to 6 rounds of 40 weekly, and I don't know if I could achieve my goal without a hybrid city taking full advantage of the Ancient Wonder Machine. Troops have a built-in strength cap - so unless I win armorers weekly and the academy blesses me with multiple opportunities to craft boost buildings - every single week I cannot see my troops completing 6 rounds of 40 weekly - the troop strength can only take you so far - regardless of troop availability.
So, it occurred to me that a hybrid city, that plays a lot of tournaments, and builds all the Ancient Wonders - will earn more seeds & unurium from the Trader, because of the increased need of the city's required culture & working population, and they will have more Ancient Wonders therefore in the end more Ancient Wonder levels.
LOL a little off topic