How to manipulate good price, make profit and level trading fast. TLDR: Get Married, Steal Wife Armor, Sell it for Starting Capital, Change all workshops in towns to same type to drive up demand and prices.
Guide to Take Profit
Building Up Capital
It is Day 1 and we need to get around 24k before we can begin The Con. You can do this anyway you want and there are plenty of good guides but for completeness I will list 2 fast ways I have used.
Steal Wife Armor and Sell it Method
If I am playing death enabled, I spec for Social on character creation so I can pass the conversation checks and get married immediately to build my clan. Find a noble with good stats ,say Ira, and get married. Once married you can take your wife's armor.
On top where the name is. Use the left and right arrow to switch to you wife's equipment and take her armor. I typically sell the horse armor (93k) and keep body armor for tournaments.
If you have a Non-Social build in early game or just don't like marriage, do this.
Go to Seonon or villages nearby and buy some cheap Sumpter horses(45-50 denar) to increase carry capacity so you move fast enough with your goods to avoid looters early game. Then start buying iron ore from Seonon and selling at Ocs or Lageta repeatedly.
Note: Faster and more fun IMO to just steal wife armor. You can even save scum in a non-social build to get married.
We want to create specialist towns with all workshops of the same type to drive up demand. To maximize the price we do this in a town that that does not have a supply.
We want to create a supply town that just produces resources and does not use it.
Find 2 towns next to each other that do not produce the same resources. I will use Epicotrea and Diathma.
Diathma: Specialist town with 3 smithy. Just buy all the workshops one at a time, change the type and immediately sell it. This loses you around 3k each time and why we needed around 24k to do this.
Epicotrea: Notice I removed the smithy in Epicotrea because i want the price to be low when i buy here. That's all you need to set up the supply town. The reason I have 3 tannery is because I do the setup with almost every town and in this save i was buying hides from the North and selling here.
Buy from Supply town and sell to specialist town
I am buy Iron Ore from Epicotrea for 25-30 and sell at Diathma for 64-70. Notice Diathma already has 142 units of iron ore but is still willing to pay 64 gold.
This method almost guarantees you can buy at green low price and sell in high red prices in neighboring towns. If you start experiencing diminishing returns it is time to repeat this for another town. You can create trade loops this way easily.
This makes you money and power levels Trading. In my experience for leveling Trading, more trade profit = more exp and trade loss = 0 exp. I am around 110 days in game (took 40-50 to get married bc I couldn't speak with Ira while in Rhagaea's Army) and my trade is already 80.