As historical accuracy goes, you may say that the supply/demand market forces were what determined commodity costs way into the 19 century. And even a country which does not have a market economy has to purchase goods on the global market, which for the most part adheres to the general principles of a market economy.

. If a city builds a clothing factory, then it turns the raw material into fur jackets, a finished good. For each fur jacket resource, it provides 1
. For example, extra gold and silver can give extra trade route yield (+25% each case) with the discovery of currency and the building of a minting factory. Tobbaco -> cigar can give +1 gold per resouce per city. Bronze and iron -> alloy can give a boost in production (like corporation in civ 4.) Oil and coal can speed up tech rate of industrial military techs.