Trading Skill Calculation

The most skill EXP you can gain from buying goods in a single transaction is 20.  However, as you level your skill up, you'll have to buy more and more goods just to get that 20 skill exp.  Here's how the formula works.

Skill level x 20 = Target Goods to buy for Max skill exp

As you can see, at level 1, buying 20 of type of good will give you the full 20 skill exp.  If you buy 40 at once, you'll only get 20 skill exp.  When you reach level 2, you need to buy 40 of a type of good to get 20 skill exp, buying 20 will just give you 10 skill exp, and buying 60 will only give you 20 skill exp.

A sample situation: let's say, 40 Dutch Calico to get max skill exp for your level 2 Fabric Trading, but there's 120 available?  Buy 40 Dutch Calico, complete the transaction, then buy another 40, complete the trade, then buy the last 40.  The total skill exp that you gained would be 60 out of that!  If you'd bought it all in one you'd only get 20 skill exp.  This is usually only possible with high quantity goods, but in a port where there's many different goods of the same type, you can use it to your advantage as well.

And that is the last thing to remember about the formula.  It cares about the total you're purchasing of a given type, not of each actual trade good.  If you're a level 2 Ore Trading and can buy both Iron and Copper Ore in the same town, if you buy 40 Iron Ore and 40 Copper Ore at the same time, you'll still only get 20 skill exp.  Buying 40 Iron Ore in one transaction, then 40 Copper Ore in the second one, will get you the full 40 skill exp.

Always remember the formula and use it to your own benefit.

Hope this might help! Happy Trading!