I believe it is impossible to measure profits in any way of form.
It totally depends on current world situation and the amount of caravans/peasants successfully trading with a city. In times of peace, where there is no demand for food and high demand for luxury items (like jewelry, steel, furs, wool, etc), a brewery would hardly touch a 200 gold profits, while silversmith is churning 400 a day. In times of all-out wars with constant raiding and sieges, food prices skyrocket and everything else becomes basically worthless. The same brewery would net you good 500 denars while silversmith would bring about 30-50.