The economy in This War of Mine is a very well-crafted system, without which TWoM would not be challenging or particularly fun. Min/maxing isn't required to win, but a decent understanding of the economy of this game is required to be successful. Since they've fixed broken areas like Central Square, it's much harder to survive purely off trading, and it's much harder to break the game without fully understanding the economy and how it functions.
A valuable skill is to be able to figure out how wealthy your household is by examining your inventory, which you should aim to develop over time as it allows you to figure out what your priorities are for your next scavenge and crafting priorities. In short, the aim is to maximise household value while also ensuring that you have a surplus of T4 items and food to survive day-to-day. In addition to this, a surplus of Parts and Materials are necessary to upgrade your infrastructure, so it's important to never neglect your stock of raw materials!
Scavenging- Item values:
It is worth bearing in mind that the item tiers is not a direct representation of how valuable an item is, but instead is about Scavenge Priority. One has to consider how well these items takes up your backpack space (i.e. you have to consider max stackable as well). For example, Sugar is dirt cheap per unit, but the max stack is 10, which equals 2.5 moonshine (or 3.33!!!! with Bruno), thus it makes far better use of your backpack space than 2 wood. Bear in mind it still requires you to have Clean Water and spare Fuel to make Moonshine, but it shows the principle that the hard value per unit is not the only consideration of this tier list.
As a rule of thumb, the more everyday an item is, the less valuable it is, and the more situational an item is, the more valuable it is.
Situational and Strong (T1):
Medical supplies and Strong Weapons top the tier list when it comes to item value. Herbal Meds alone gets 20 components from Franko, making it extremely efficient when it comes to Backpack space. Herbal meds are the cheapest item in this tier as well, so a good scavenge of all the Meds and Food from an area can suddenly boost your household value from poor to wealthy in one scavenge (if you have a decent backpack space anyway). Plus, meds all have 2 as their max stackable, giving insane backpack space value! The Shotgun and Assault Rifle are fantastic trading items and if you can build a surplus of them you're probably going to win off Franko alone (certainly with Katia in the group).
Everyday but Necessary/Situational (T2):
Raw Food, Vegetables form the Everyday but Necessary group. Canned Food is Situational and also quite a bit more expensive than Raw Food and/or Vegetables.
Expensive and/or rare crafting components (like Pure Alcohol, Med ingredients), trading items (like Jewelry) and situational items (like Moonshine) are also T2. They are either unstackable and valuable (e.g. Moonshine) or less valuable but stackable (Pure Alcohol, Jewelry).
Weak weapons like the Knife and Pistol, and higher tier equipment like the Hatchet also fall into this tier.
Rarer everyday stuff/Rarer Crafting Components (T3):
Filters, Electric Parts, Parts, Weapons Parts, Sugar... Basic tools like Sawblades as well. These form the third tier of item. Good to scavenge but often hard to stack to the point that you'd take it over anything else, even sometimes forgoing them for T4 items because you can't stack them.
Broken Weapons are T3. They can't be stacked and trade at far, far less than their repaired value: don't trade these unless you're desperate!
Everyday stuff/ Basic Crafting Components (T4):
Components, Wood, Fuel, Clean Water, Cigarettes, Coffee, Herbs, Books... the rest falls into the bottom tier. These things aren't worth scavenging directly for unless: a) You've got a specific need for them the next day; b) There's spare room in your backpack (Relatively common occurence with Boris); c) It's winter and so you need to scavenge more materials in general.
Trash Tier:
Gunpowder and Shotgun Shells are Trash Tier, in my opinion. Sure, they stack well, and they can be used to make ammunition, but in reality Ammunition is not all that rare, and you can often clear areas to find a respectable amount of it. Also, it's worth considering that the Advanced Metal Workshop which makes use of these shells and gunpowder is a luxury late-game workshop upgrade, and thus it's not really
Crafted items range from T4 all the way to T1, so they will be discussed separately.
Franko the Traveling Salesman
I've heard a lot of people complain about how Franko's prices are ridiculous, and it's true that he does charge a premium. However, there's an excellent reason for this, and that's because he provides two efficiencies:
a) You don't have to expend a Scavenge to trade, and yes, scavenges represent time and thus value. Without the game-breaking Central Square anymore, it's impossible to get a Trader who makes you filthy rich off one roll-up cigarette. There are other broken traders, but generally they don't provide all the materials you could possibly want in one convenient location. Thus, you're choosing between scavenging a location for free or simply trying to trade: most times you'll simply want to scavenge. b) More importantly, Franko ignores the Backpack Space requirement. This is crucial: if you need raw materials, even the most successful trade with Katia can only bring back 12x4= 48 components, or less if it's a mix of components and wood. However, if you trade with Franko, you can get ALL of his components (often 30+), all of his wood and fuel (often 30+), and all of his useful raw materials (Clean water, parts, weapon parts, sugar etc). Basically, you want to trade in all your spare T1 and T2 items for all the T4 and T3 items that you want.
So let's consider trading meds for components (without Katia). Throwing in all your excess T1 and T2 items, you can trade in all the excess T3 and T4 items that you want. One Medications will net you 31 components. And it's stackable. So if you bagged two spare Medications on a Scavenge that's 62 components in the bag, or 15+ slots of components when it comes to Backpack space. That's right, even Marko couldn't carry all those components. And best of all, the 2 Meds took up 1 space. Thus, you can trade off Excess Meds and/or Weapons (with some lower tier sweeteners) to clear Franko out all game.
One might ask, why buy consumables/ Clean Water? This is a legitimate question. The reason that you should almost always buy these lower tier items is that these represent Components and Wood. Fuel is just chopped up wood, but buying in fuel means you can use your wood for crafting instead of fuel. Clean water is basically crafted components, and components+ wood in the winter. Similarly, you can craft a Crowbar and sell it back to Franko with Katia at a profit, but that's now 10 components that you can't use for other tasks, or more importantly, upgrading your infrastructure.
Thus, Franko allows you to do two things. Firstly, he is what justifies you scavenging the most valuable items with high priority and only grabbing what T4 items you need to survive day-to-day. Most pushes for infrastructure can be made with either a high-% scavenge (after all the valuables are gone) or Franko trades. Secondly, he allows you to balance the resources in your household. Got a shortage of vegetables? Trade for it. Got no use for these herbs right now? Use it to sweeten a deal on top of bandages. Basically, Franko is OP, and abusing his efficiency, in addition to balancing out your resources, is what I consider the most game-breaking aspect of the game right now.
Infrastructure:
Infrastructure is what sets apart those who are merely getting by, and those who are flourishing. A good indication of how well you're doing is how much infrastructure you've set up, because without it you're wholly reliant on what you can scavenge and not what you can craft. Without the ability to craft, your days are basically wasted and you will add zero value to your household during a day, which as I've mentioned before is a waste of the resource of time. Instead, your household will consistently get slightly poorly during each day. Food will be consumed. Clean water, components and wood will be expended. Meds and Bandages used (ouch). However, with infrastructure you can balance your economy, or cause yourself to get richer over the course of a day.
Traps for small animals is a great example of this. At a decent initial cost, it allows you to convert Fertilizer into Raw Food or invest Raw Food to get more Raw Food down the line. Eventually you'll have two up and running, which causes a good amount of Raw Food to be generated. Eventually combined with smart scavenging and trading you'll be self sufficient for many days past the final day.
The Improved Workshop and Improved Metal Workshop are definitely upgrades one should beeline for. On the side of the Improved Workshop, Board Ups are a baseline necessity to maintain Household Value, as it protects against raids. Successful raids are the bane of your existence, often taking away valuable resources, causing you to expend bandages because your survivors become wounded, or even making them sad. Improved Metal Workshop is also a godsend, as it allows you to craft Sawblades (crucial for getting a lot of the best loot) and the Hatchet, which is one of the best craftable transitional items in the game. For an initial investment of Weapon Parts and wood, a very substantial reserve of Fuel and Wood can be obtained by chopping the redundant furniture. It doubles up as a fine weapon on the defense and a strong backstab weapon on the offence. If it's a winter start, or an autumn start (day ~4 you need a heater), one should consider the Improved Metal Workshop as your first workshop upgrade simply to access the Hatchet.
The Herbal Garden and Herbal Workshop in combination creates basic crafting opportunities, but it needs to be augmented with a Alcohol Distiller to start crafting valuable items (like Bandages and Herbal Meds). In reality, the Herbal Garden is pretty useless without access to Pure Alcohol, and the Herbal Workshop can only make cigarettes without Pure Alcohol. Thus, you actually need to access the Advanced Workshop to really get your economy going, which introduces Electric Parts into use.
Electric Parts
Electric Parts are resources that are required to reach the middlegame of your infrastructure. Firstly, they're required to Upgrade your Advanced Workshop, which then allows you to Craft 3 different advanced parts. These advanced parts give access to the Alcohol Distiller, the Vegetable Garden upgrade, the Advanced Metal Workshop upgrade, the Improved Heater, and the Improved Herbal Workshop. Electrical
The Alcohol Distiller should be a priority for the middlegame, as it opens up crafting of Herbal Meds and Bandages, vastly improving the wealth of your household. Herbs at this point become much more valuable, since they're directly used to craft these, and only a Herbal Workshop (which is a relatively cheap workshop) is required to access the option of crafting these items. The Improved Heater should be made a priority for most playthroughs, certainly a summer start, since at some point brutal winter will hit and a Simple Heater won't allow your survivors to stay warm, even with max fuel running. For winter starts, it's often hard to acquire the Improved Heater before the worst of winter passes, since the Advanced Workshop is a prerequisite. However, it can still be a worthy upgrade. Figure out how valuable the Improved Heater will be for you, then make your decision. Bear in mind upgrading the heater wastes all the Fuel that the Simple Heater was burning.
The Vegetable Garden is a good and valuable upgrade for the Herbal Garden. Raw Food is much more common than Vegetables are, even though their value during barter is very similar. Rat traps being lower tier than the Vegetable Garden also contributes to Vegetables' rarity. It's definitely worth getting a Vegetable Garden if you can get it quite early, since cooking Vegetable meals is by far the most economical way to feed your survivors. Bear in mind Vegetables take 1 hr to place and 72! hours to grow.
The Advanced Metal Workshop is a luxury upgrade that allows you to repair Shotguns, Assault Rifles and
Scavenging- Adjusting Priorities:
There are multiple reasons why one should adjust your priorities while scavenging. The most obvious example would be when one is badly in need of raw materials and can't wait around for Franko, or the player wants to make a big push for infrastructure.
There are multiple dynamics at work in this game. Inflation/Deflation is a minor effect, but especially worth considering when you're going to be using Traders often.
Another example would be adjusting to match the survivors that you have. For example, in the Cveta/Anton start, you're going to primarily relying on a barter economy, since they both have terrible backpack space. Thus, the player is practically forced to scavenge a bare minimum of T4 items, while primarily focusing of food for survival, and Meds for trading. Furthermore, since you have Anton, it's worth beelining for the Rat Traps to take advantage of Anton's unique ability, and also prioritise Board Ups, as there is a lack of a strong Guard. Thus, a clear gameplan is created, and by extension a clear scavenging plan.
(Semi-cheating): Broken Traders
Crafting
Efficiency
EDIT NOTES: Much to do.