The different biomes and resource availability is actually pretty cool, it makes caravans a thing. Every city has resources that are easy to get and cheap. Bridgewatch (steppe) is hide, Fort Sterling (mountain) is metal, Lymhurst (forest) is wood, Thetford (swamp) is fiber, and Martlock (highland) is stone.
Then Caerleon is generally pretty evenly priced on all the resources since it's at the center and has access to every biome via the black zone portal, but there T2 and T3 resources are expensive since it's so far from the low level zones that they spawn in. But from what I've seen it's cheaper on the higher level resources. Oxen are cheaper in Caerleon too lol, I believe it's because PKs are killing caravans coming in and nobody really wants to ride an ox out of Caerleon.
So you have caravans running from Caerleon to the outer cities with high tier resources and caravans coming in with T2-3 resources. My last trip from Thetford to Caerleon I ran across a group of 6 people riding oxen and 2 people on horses watching their backs. Then folks run between the biome cities too bringing resources from high to low availability - one guy was telling me that he made over a million silver just riding resources between the biome cities on his ox and skirting the blue (safe) zones on the edge of the map. Zero risk, can be pretty profitable, but kind of boring - and doesn't net you any fame to level up with. Biome cities to Caerleon is high risk and higher reward.
Just make sure to check the markets (you can travel freely naked) to make sure people haven't flooded the markets of a city before doing something like that. The other day I think a bunch of people ran metal from Fort Sterling into Caerleon because the T2 metal market got flooded. It dipped from 40s per ore down to 10s per ore. I think it was only 5s in Fort Sterling though so the folks running it in still make a profit.