I think, that how much merchant generates depends on resource type, distance from capital to nearest type of this resource (moving capital can help here, but it can hurt a lot other things) and merchant skill. That is all obvious.
But not so obvious is that it depends on other things. Trade rights, developement (eco bonuses & number of trade routes) of province resource is placed in. And developement of target provinces. So best is highly developed distant province with expensive resource. I have merchant that generates more than 1000 per turn and probubly other people have even better (merchant costs 550, so he pays himself in one turn).
Bookmarks