A long time ago. Final fantasy III came out with a new approach to learing magic. The characters would be equipped with espers(magical beings) and as they fought more battles, they would learn spells from the espers. What if a similar approach to learning magic was applied to a P&P rpg?
What to export or import....
Fabric: wool, linnen, silk...
Wood: raw-material, furniture
Metals: iron, gold, silver, copper...
Wine, beer, mead, spirits...
Animals: horses, sheep, swine, cows...
Coloring-powder (for fabric, ink...)
Raw-material to make fabric: unprocessed wool, linnen, silk...
Glass: Windows, figurines, glasses, raw-material...
Tea (not sure about my spelling here, but I mean the hot drink Englishmen drink instead of coffee!)