I brought this up in the IRC channel and it was suggested I post it here:
I think item values are broken in the current version, because the multipliers for material and quality lead to unrealistic results in many cases.
For instance, an exceptional marble statue, which reasonably would be exceptionally valuable just on artistic grounds, is dwarfed (forgive the pun) in value by a merely well-crafted iron statue. Similarly, two basic crafted swords, one silver and one iron, are worth the same amount; in reality, a silver sword with no artistic merit would probably be worth no more than the silver it was made of, while an iron sword of any quality is useful as a weapon.
I propose that instead of item value multipliers working on each other, they add value separately. Each item would have a few separate values: For instance, at least an "artistic" value and a "utility" value. All of the values would multiply against the base item cost separately, but then add to one another. Some examples:
A shale earring would have a utility value of 0 and a material value of 0 (because total item values aren't multiplied against material costs anymore, material values of 0 for stuff like plain rock makes sense now). Its value would be based solely on the artistic quality of the item - assuming the base item value wasn't changed, that would be 10 for a basic crafted item, 20 for a well-crafted, etc.
A shale mug would have a positive utility value (probably a minimal one, like 1) no matter what the quality. A mug that holds beer is worth something to a dwarf no matter how well-crafted it is. It *may* also have an artistic value, depending on quality.
An iron sword would have a minimal material value - much lower than the current x10 multiplier. The value of a sword is in its utility - any functional iron sword would have a high utility value, and a well-crafted sword is more useful in combat so it would have an even higher one. A well-crafted sword may even have additional artistic value.
A silver sword would have a higher raw material value, but a much lower utility value - a poorly crafted silver sword is worth barely more than the silver that was used to make it. A masterwork silver sword would still have a lackluster utility value, but that would be dwarfed by its artistic value - because it is only useful as a showpiece.
An obsidian sword would have to have a utility value far below a steel sword, due to the realistic immediate blunting and breakage of that kind of weapon. Even if weapon breakage isn't implemented, it would be unrealistic and unbalancing to clean out a caravan with a few obsidian swords.
The specifics of how this would all work are open for debate; I just wanted to see if anyone else liked this idea. One of the benefits of this kind of system is that it would open the door to new kinds of values and preferences that weren't practical before. For instance, elves could multiply artistic value, and dwarves could divide material value because dwarven civs are already awash in precious metals. Someone suggested in IRC that there could be a "historical" value for items that belonged to legendary figures, such as a crown found in a king's tomb in adventure mode. Adding new modifiers like that would be difficult in the current system because multipliers would result in ever-more ridiculous values, but a more toned-down additive bonus would be reasonable.