Discworld command help
value - values objects.
value <object> in <currency area>
With the value command you can estimate the value of clothing, weapons, armour, gems and jewellery. The value command will also give you information on the laundering history of the item if you are a thief.
The skills used to value items are the various people.trading.valueing sub-skills and the player will have to have five guild points available for people commands to execute the command.
> value knife
You estimate that the knife is worth A$8.24. You can also see that it has been modified more than once.
> value earrings in lancre
You estimate that the pair of cobalt earrings is worth LC 2|7|3. You feel pretty sure that your estimation is in the general region of the real value.