Yup. "Fair Trade" is the label some people put on that. Here is the reasoning:
Takes 1 labor to make a raw lux mat. Takes two raw lux mats plus one more labor to make a lux good. So a lux good takes three hours to make but a raw mat only took 1 so the trade ratio should be 3:1.
Sandals and Sculptures are actually worth more because they use four reeds or clay in addition to two lux raw mats. They should run at 3.8:1. Most people don't bother with a different ratio for them because (a) 3:1 is easier to calculate and (b) people rationalize that they are "easier" to make because they only use one type of lux raw mat.
The market price is set by local supply and demand. Local shortages can mean great profit to local suppliers (just ask the Nubian Traders
). Local gluts can have the opposite effect (I have seen Limestone offered at 0.5 bread per and sit their for days).
If you can sell all your excess raw mats for 4 or 5 in the market, then chances are that is a better deal than trading them since most lux goods go for 11 or less (at least in mature markets - not so much in an undeveloped market). You just have to see what is selling at what price on the market before deciding what to trade - asuming you want the most you can get for your labor/bread. Don't forget the market has a 10% fee.
If you really want to get into the details, then check out the
spreadsheet.
