While it happens that blogspot seems incapable of producing comments on the last post (I know of two that are not showing on the page), I'll just repeat here to Adam that while I found his comeback very funny, I don't actually have any intentions of incorporating any of the things he suggests from point (3) on down. Ever.
He is, however, quite right about point (1): I do know the amount of raw materials available in my world. Sadly, point (2), that I have a pretty good idea of what kind of labor any given item will require to produce, is dead wrong.
In actual fact, I haven't the slightest idea.
Consider, if you will, a sword. It is made of metal, which is fashioned from a variety of ores - namely, an alloy of iron, nickle and manganese. I know how much of those three substances are produced in my world, and I can calculate the price of the sword from the availability of those substances, and from the availability of services to make the weapon. Unfortunately, that 'availability' is calculated according to an abstract economic model which does NOT incorporate labor. Why? Because stats for labor don't exist. They simply don't.
Let us say that we know how much rock a miner can clear in the space of a day. Does that give us any idea of how much ore he produces? No. Ore exists as a percentage of the rock, a percentage that varies widely from mine to mine, worldwide. Whereas one miner might find that 4% of the rock cleared is valuable ore, another miner might be working a vein where every ounce is. Or it may take weeks, months, even years of solid work to get to that vein ... work which produces no economic value at all. Knowing that a set amount of ore is produced from a given mine gives me no idea whatsoever how much labor was needed to produce that ore. It doesn't even suggest how many miners might be involved.
Farming is exactly the same ... though some might assume otherwise. But while the grain in a particular field might grow over a given, measurable period, this does not tell me how many people were employed in sowing, weeding and harvesting that grain. I have anecdotal accounts from the medieval period that says one family typically lived on 30 acres of land - but how large is the family? How many of the children contributed to the labor? To what degree does the production of the grain depend upon temporary workers, which we know were employed by peasants? (cotters and such were landless peasants who performed labor in return for food)
And in any event, knowing how much labor it required to produce a field of grain gives no clue or comparison to the number of men needed to produce the ore in the above example.
Add to this that even if I knew how many laborers might work in a mine that produced such and such an amount of ore (which I don't), this wouldn't be any help in knowing how many it took to puddle the ore, or smelt it into the alloy, or even how long it took the blacksmith to hammer the metal into a sword. How much of the blacksmith's time was wasted in having to reforge a weapon in which an impurity in the metal itself occurred? How much longer did it take to make a broadsword as compared to a cuirass? Was it less time?
We simply don't know. Such information, for every conceivable item that a D&D player might purchase, has never been recorded. Modern measurements of time to do work are useless, since they are post-industrial ... and at any rate, they'd be a lie. For instance, how long does it take to do your job, compared with how long your boss thinks it takes? Why would the medieval world be any different.
It has been a long-time head-scratcher, to be sure, contemplating how to calculate a day's wages from the production of goods. It is frustrating that I can know a particular city is responsible for the production of a given percentage of the world's swords (or processed tobacco or apple cider or felt hats), but I haven't the first clue how many swordmakers there are.
I'd love an encompassing strategy to solve it, because all too often my parties want to hire people and I'm stuck throwing darts at a dartboard.