I somehow missed this. This is the most wrong you've ever been on this forum. This is "squaredancing with gnomish paladins wrong".
The cost of living is *the central economic value* of D&D. Everything else is centered around it.
If you don't know the cost of living, and you're being offered 50 gp for a dangerous quest. Is that a lot of money? Who knows!?! The cost of living informs you how much that 50 gp is worth.
It's also the foundation on which other prices are built, or at least hopefully. Cost of living is 10 gp/day, swords are 2 silvers.... doesn't make sense.
Plus it's based on research Gygax did about the salary of a laborer in ancient Greece I believe, so it's not entirely without foundation.
(further reading
https://slugsandsilver.blogspot.com/2018/08/your-economic-yardstick-laborer.html )
So, a few things.
First, I resent the comment that this is the most wrong I have ever been on this forum. I pride myself not just on my wrongness, but on the magnitude of my wrongosity. You, sir, take that back. Even assuming, arguendo, that this is wrong, this is not even in the top half of wrong comments I have made. I aspire to, and achieve, a higher level of complete and total incorrectness than this particular comment!
Second, that wasn't my point at, all. I mean, the entire point of my post is that the economy in D&D is completely made up- which is true by definition, since it is static, and it presumes that it is worldwide, and it ignore supply and demand (but that's what the rest of the post you excerpted from said), but let's dig deeper on just the point you quoted, using your post and your linked-to blog that you wrote in.
Now, the most interesting thing is that you state that it's based on research Gygax did on being a laborer in ancient Greece, and that it's plausible because the going rate in ancient greece was half a drachma to "provide" for a poor citizen (4.3 grams). Now, let's see what Gygax actually did in OD&D and 1e.
1 coin = 1/10th pound = 45.36 grams
Unskilled Labor comes from, inter alia, the standard hireling table, p. 28 DMG, bearer/porter, 1 s.p. per day.
So the unskilled laborers in Gygax's world were making approximately 10x the amount that research would show.*
Of course, how do we know that Gygax most likely didn't do full research and, instead, was pulling numbers out of his posterior gor gamist reasons? Well, let's see. PHB . 35- "Your character will most probably be adventuring in an area where money is plentiful. Think of the situation as similar to Alaskan boom towns during the gold rush days, where eggs sold for one dollar each and mining tools sold for $20, $50, and $100 or more. Costs in the adventuring area are distorted because of the law of supply and demand - the supply of coin is high, while supplies of equipment for adventurers are in great demand."
Anyway, the gist of all of this is that AFAIK, it really was without foundation. I don't happen to agree with S'mon that 1 to 2 SP per day was the "living wage" for thousands of years in places with a monetary economy (again, source). Wages (including in-kind contributions such as food and lodging) varied in different areas and over time; notably, issues such as war and disease (the black death, for example, was a major driver of wages in Europe, and similar population issues had similar effects throughout history) would drive wages, while relative wealth between areas also mattered a great deal. Finally, the idea of static pricing would, of course, preclude any kind of trade, as there would be no opportunity for profit from carrying the rubies from the countries that have them to the countries that don't (Spice Road, etc.).
In the end, my argument in this thread has been, and always will be, simple and two-fold.
1. TTRPGs won't model economics very well- use whatever works for your immersion.
2. This is even moreseo the case once you introduce magic into the economy; you know the old standby of "Any sufficiently high technology is indistinguishable from magic?" Well, magic (assuming there aren't countervailing forces, like hunting down all people and items that use it) would end up having similar effects to technology, and while we could try and model some effects (total difference in tactics for armies due to area effect spells, massive increases in spying and espionage and countermeasures between nation-states, and so on) it would be impossible to understand the effects on the economic system, so most people either don't bother, or just make it a cool feature (Eberron).
But yeah, like bathroom breaks and sanitation in cities, the underlying economy is something that is not really worth the time in the TTRPG to model. IMO.
*Assuming that this is where he got the figures. Could you cite a source for this? It's sounds like something he would totally do, "Eh, Ancient Greece, close enough, who cares about the weight ...." but I don't remember seeing this contemporaneously sourced out before. Would love to see it!