There is still unresolved points: how to account for the quality of the good and eventual decorations? They might act as modifiers on the final price. And could golden statues be less expalsive than lead ones in some extreme cases?
As far as decorations are concerned, I can see how in some cases, they could actually
reduce the value of the finished good: If they are of noticeably lower quality, and/or of much lower material cost, than the base item, then they effectively
mar the item's beauty and make it look cheap. In extreme cases, this could be considered vandalism, albeit unintentional. If you have a +gold statue+ and embellish it with some masterfully-placed brilliant-cut almandines, then that's a considerable improvement. But if it's a ☼gold statue☼ and you
mangle the work with your clumsily-laid hunks of schist, then you've made the king look like a beggar! Shame on you!
Theoretically, lead statues
could be worth more than gold ones, although it's rather unlikely, and largely for reasons that would make them worth
less than the equivalent of bars of the same metals. As far as DF is concerned, gold & lead are just as useful: Gold's advantages of being ton-toxic, non-tarnishing, and a great electrical conductor aren't included in the game, and both metals are almost equally soft & ductile, so really the only reason to prefer gold is that it's more shiny. And the only reason to prefer
lead is because you've got some noble with a material preference. But if you desire lead for the lead
itself, then finished goods should actually be worth
less than the raw metal, due to the emotional pain that the buyer knows he's going to feel when he melts the artwork back down.
It will be necessary for us to slow down the productivity of our dwarves per hour in order to guarantee a certain quality of an item be produced. That is because a totally random production of high-quality items means that since no greater amount of labour was used to produce them than the lower quality items, so the numerical value of such items is the same as that of lower-quality items.
No. Masterworks represent an investment of labor by a highly skilled dwarf as opposed to the same investment of labor by an unskilled dwarf. Skilled dwarves are rarer. Masterworks are subjectively more pleasing, and objectively superior in combat. This alone is sufficient to give masterworks a higher price.
The time/labor costs of an item's production are largely irrelevant to a buyer, and should therefore have no impact on the item's price. Where they
are relevant is on the artisan's
desire to produce that item: Things that take a long time to make but give only a small return simply aren't worth the maker's time, so of course he chooses not to make them, which creates scarcity, which drives the price up, which makes the item worth making. But in DF, there are three things that break this natural equilibrium: 1) Dwarves don't make capitalisitic decisions in a communist society, 2) Dwarves have no qualms about doing non-cost-effective work, especially when there is often
literally nothing else to do, and 3) Legendaries can and will do the same job in the blink of an eye, effectively making the entire concepts of "labor costs" and "competition" obsolete.
Suggested improvements:
More realistic timeframes, for all products. No Mason, no matter how Legendary, should be able to whip out 15 stone weapon racks in an hour--just as no Cook, no matter how Dabbling, should take 3 days just to prepare some stew.
Smaller speed increases as an artisan gains ranks in a skill . . . perhaps even none at all.
Revamp the creation process into a multi-step one, rolling the "quality dice" each time. As the craftsdwarf completes an item, he compares: 1) The time he's taken on it so far, vs. the "average" time for that type of item, 2) The quality level of the item, vs. his own level of skill, 3) The quality level of the item, vs. the odds that any further work would be an improvement, and 4) The time required for further work, vs. his own needs for food/drink/sleep.
IF the craftsdwarf is a) not too far behind schedule, b) unsatisfied with his work so far, c) fairly sure that he could do better,
and d) not too distracted by physical needs, then he should try to fine-tune and/or salvage his work. Roll the quality dice again, and maybe he'll improve the item, maybe he'll make it worse, and maybe he'll screw up completely & wreck it beyond repair. So the
main reason that Legendaries can do work so much faster than other artisans should be because they got it right the
first time.