[TCArknight]

Ok, I'm wondering if this is possible.

1) I have a gizmo helper, AmmoHelper, to help with the gizmo (ammo) for a weapon.

  
  <component
    id="AmmoHelp"
    name="Ammo Helper">
	
    <!-- Gear cost -->
    <field
      id="WeaponBaseCost"
      name="Weapon Base Cost"
      minvalue="0"
      defvalue="0"
      type="derived">
	  </field>
	  
    <!-- Selection Tag Expressions -->
    <field
      id="AmmoExpr"
      name="Equipment Tag Expression"
      type="derived"
      maxlength="500">
      </field>

    </component>

2) The cost of a full reload for a weapon is 20% of the cost of the weapon. On the particular ammunition, the grCost field is set to 1.
3) This script runs on the ammo itself -

(Render/100)
~make sure we're in a gizmo to travel to
doneif (parent.isgizmo = 0)

var parCost as number
var myCost as number

parCost = parent.field[grCost].value
myCost = parCost * .20

field[grCost].value = myCost
parent.field[grCost].value += myCost
parent.field[wpDamage].text = field[amDamage].text

When I click edit to add ammunition (frag grenade reload) to a weapon (grenade launcher), the cost displayed in the field value (when selecting as a thing) is always the set cost in the grenade's cost field.

Is there a way, when is it a Thing instead of a Pick, to use the BaseWeaponCost field from the AmmoHelper to calculate the cost to be displayed?

Once the ammo is added to the weapon, the Total Value of the weapon and ammo (the weapon cost + 20% for the reload) is correctly displayed.