Resources?

[TiTiTimmy]

What does this actually means?

type gold
trade_value 20

[Dietre]

i believe it adds the gold resource to ur cities trading resources at 20 florins per turn

or its a multiplier for ur merchant when u position him on it to trade it

[Gigantus]

type = one of the categories of trade resources
trade_value = base value for calculations that are governed by modifiers like distance to capital, experience level of the merchant, level of building in settlement.

[TiTiTimmy]

So how much gold is the value 20 worth, because I want to improve some resources but not so they are overpriced.

[Gigantus]

If you have a look in the descr_sm_resources file you will see that gold has pretty much the highest value, silk is very high priced as well. If you want to increase your income I suggest the following:
Instead of increasing the value (local settings) you might want to change the modifiers (global settings) in data\descr_settlement_mechanics.xml (open with notepad):

        <factor name = "SIF_TRADE">
            <pip_modifier value = "0.80"/>
            <castle_modifier value = "0.80"/>
            <city_modifier value = "1.0"/>
        </factor>

or descr_campaign_db.xml:

   <merchants>
      <base_income_modifier float="1.25"/>
      <trade_bonus_offset float="15"/>
   </merchants>

Play around with the values but don't forget to backup!