most valuable resorces

[Ramses II CP]

Among the top 5-6 most rare types of merchandise florins earned has more to do with the location of your capital than with the relative value of the item. I find it's easiest to just check the economic report between switching my capital around after I've placed merchants on all the premium resources nearby. Try to place your capital as far away as possible from the nearest instance of a particular item that your merchants control.

[Yoyoma1910]

It also seems somewhat driven by what your faction has access to. For instance, I've noticed as Portugal that the iron resources in Spain are substantially more valuable than if I'm playing, say France.