Yeah, it seems a bit weird to have some big colonial capitalism trading monopoly empires without some of the most important trade goods of all time... narcotics! *rule britannia intensitifes* While Opium is almost certainly the most important (speaking in Civilization game terms) luxury item missing in terms of historical signifigance, some others that I'd like to see are spirits (liqours), cocaine/coca, leather, and lumber (lumber could spawn in certain woods and rainforest; let's just say it's a special kind that's uniquely valued, like Mahogany). The following would be more like strategic resources but I'd also like to see medicines and steel. We do have iron already, but the steel trade was an absolutely huge part of world capitalism in the last few hundred years, and somewhat remains so. Personally, I'd like to see strategic resources become more important for non-war tasks. I think tier 3 buildings should require steel (1 iron + 1 coal, like railroads) or concrete (how about after a certain tech, stone and marble quarries yield conrete as a strategic resource). Maybe I'm getting a bit off topic, so back to monopolies, I think corporate espionage/intellectual property could be important as well.