Trading for a Profit
As with all Mount & Blade games, you can take any item in your inventory and sell it for different prices at different settlements. This applies to any loot that you acquire, but you can also take any item from a merchant in one settlement and immediately visit another to sell it for a profit. There is an additional mechanic in Bannerlord which hints at the value of any given item. This comes in the form of the value being represented by the colour green, orange, or red. Any value which is green indicates that it is being sold for a good price at that specific location. Yellow is neutral, indicating an average price. Red means that the item is being sold at a higher value than it is elsewhere.
You can visit any settlement and check its goods under the Trade tab to determine which items can be bought or sold for a profit. For example, if you find the price of pottery in one settlement is green, you can purchase this here and then seek out nearby settlements to sell it for a price higher than what you originally paid. The profit is usually minimal, making this method a little tedious at times, but some items can be sold for profits of 30 - 60 denars per item. With a dozen or so of these, the effort can certainly return a hefty profit if you prefer trading over fighting. Aside from checking each individual settlement for their prices, you can also interact with merchant caravans on the road to ask for information about where to sell specific items for a profit.
In general, the regions where specific items will sell for a profit correspond to their rarity in that region. For example, furs are produced parimarily by the Sturgians in the north. This means that furs will be difficult to find in the south, and will sell for an above average price in southern settlements. Similarly, dates are only sold in the south of Calradia, so purchasing a few there and selling them up north will return a healthy profit. Some regions are completely deprived of specific goods, making them extremely valuable. Examples of this include salt, which isn't produced in the north east, while cotton is only found in the north east. As your skill in trade increases, you will learn more information about where to find the best prices for specific goods, as detailed below.
Note: The amount of information that you can obtain about any given trade item will increase as your skill in Trade improves. You can increase your skill by purchasing items at a below average cost (those marked by green prices) and then selling them at a higher than average cost in a different town (noted by the price now being marked as red). When your skill in Trade is high, you will be able to hover over items to see hints about specifically where to sell them for a profit.