foundryvtt-reve-de-dragon/templates/sheets/item/common/template-inventaire.hbs

<fieldset>
  {{formField systemFields.qualite value=system.qualite}}
  {{formField systemFields.encombrement value=system.encombrement}}
  {{formField systemFields.quantite value=system.quantite}}

 <div class="form-group item-cout">
    <label>Prix (sols)</label>
    <div class="form-fields">
      <input class="attribute-value number-x3 {{#if (and (eq item.type 'monnaie') (eq system.cout 0))}} field-error{{/if}}"
        type="number" data-dtype="Number"
        name="system.cout"
        value="{{numberFormat system.cout decimals=2 sign=false}}" 
        {{#unless (isFieldInventaireModifiable type 'cout')}}disabled{{/unless}}
      />
    </div>
  </div>
</fieldset>