That's literally the meaning of what I said.
Which is why I concluded it's unreasonable for basic necessities to cost that much. The only thing we know is that clothes used to cost a buttload of money for a commoner, which doesn't make sense since commoners also use clothes almost all the time.
I don't agree with that assumption. To me it seems to cut things out for the purpose of it being better for your argument without any justification why. They say they can live off of 180 coins for a year. That has to include all expenses they will face over the course of a year, since otherwise they can't live off of that sum of money.
A house is a basic necessity (strictly speaking "shelter"). Most people didn't build their own houses. So it's not true for all basic necessities. Tailoring is a high-effort skill, and one that's rarely used outside simple repairs. It's one of those crafts that's more often than not outsourced to specialists who can do it faster and for less cost. Sure, some families would have someone who could make clothes. But not all, and enough would not have it to create a reasonably economy for ready-made clothes.
Overall, there are more plot holes, inconsistencies, and general unreasonableness to take it as written than to take it as a mistake by the author.
I don’t agree with your arguments, as they do not account for the material costs and technology (or rather the lack of it), which mine took into account. In addition to the economics aspect that I mentioned on luxury clothing articles (or any goods), such as transport costs. Keeping in mind that skilled craftsmen typically reside in specific areas, such as near the gathering/harvesting area.
Here is the quick math that I did when I originally finished reading the chapter:
Assuming a clothing takes 6 man days to make manually by hand (unlikely as spooling threads, weaving, dyeing, sewing manually will take longer), with living cost of 1 gold every 3 days per person (lower than adventurers).
With 1 gold worth of materials (would cost much more if they need to hire adventurers) before the craftsman makes any money is 1+2=3 gold.
To feed their family (say 1 partner + 2 children, which is minimum to retain population), then they want to make at least 3 gold from that, so we then have production cost of a clothing article 6 gold (material + labor).
This is a severe underestimation to my original assumption and perhaps closer to your assumption, though we can see from this that the craftsman barely make anything, even if we were to switch to 1 gold per person per day living cost.
Such cases are unlikely for someone in a vital occupation with years of training.
The merchant would pay adventurers guarding him roughly 20 gold / per person / per day for adventurers about the same ranking as Will. The transport process is easily days/weeks with a wagon pulled by a horse.
With party of 3, over a week, that’s an overhead of 420 gold. If the merchant carries, say 100 articles, that is 600+420=1020 gold.
Now there are taxes, food, warehousing, horse feed, staffing pay, etc for the merchant. Based on how adventurers are paid, we can imagine these costing hundreds of gold, but let’s say they total on the lower end of roughly 180 golds, which brings the total to 1200 gold.
Meaning with transport costs, the item is now 12 gold each before profit or mark ups. Clothing typically marked up anywhere from 100-300%, with 100% markup, the item is now on sale for 24 gold.
This is from choosing the lower values and underestimating at almost every step.
From this, we can see that a 6 gold item is now easily being sold reasonably for 24 gold accounting for transportation and profit, perhaps more in big cities where such records are typically made.
We can imagine the change with the magic, now every settlement has multiple mini clothing factories, hence transport, middlemen and other overheads disappearing, lowering down the price significantly.
Also, keep in mind as well that 1 gold in this series is most likely not worth as much as the ones in other Japanese fantasy series. They use it to discuss daily living costs, while other series would usually go in copper or silver for the same topic. It’s better to think of it as unit instead of material.
On the other point, you can’t compare building a house to making sundries. If you want to compare, woodworking would be closer: plates, bowls, or even ropes. The basis of my assumption in this is that historically in the past, families in tribes and villages produce their own clothing for their own use in way back, especially during winter. Some work on elaborate pieces for dowries as well.
Anyway, this story doesn’t come with a big block of detailed texts explaining how their societies work (for the better). However, what’s clear is that in any business the cost is more than just material + labor of one person supporting himself. As an item moves around, especially through an inefficient dangerous network, the costs goes up significantly.
Now, the story is not perfect, but I believe the numbers following the flow of goods are reasonable as per my explanation. If you still disagree, which you are perfectly entitled to, then let’s just agree to disagree.