by dcorban
There are quite a few interesting comments in this article.Tannery was given the limit of 4x to encourage players to hoard cattle. Smokehouse was given the limit of 6x to give a target number for players to acquire.
Meat was given a value less than cattle so as to not make using the Slaughterhouse an obvious choice. Iron was given a relatively low value to encourage the use of it, instead of shipping it, to keep the game interesting. The same with bricks.
The subsidies (francs awarded when converting goods) are there to help balance the value for each good against its energy and acquisition cost.