Ubercart

      $op_costs = 0;
      $op_prices = 0;
      $op_weight = 0;

      foreach ($options as $option)
      {
        $op_costs += $option['cost'];
        $op_prices += $option['price'];
        $op_weight += $option['weight'];
      }
     
      $item->cost -= $op_costs;
      $item->price -= $op_prices;
      $item->weight -= $op_weight;
     
      $item->cost *= (!empty($op_costs) ? ($op_costs / 100) : 1); //If no percent-value is set, take the default value by multiply the value with 1.
      $item->price *= (!empty($op_prices) ? ($op_prices / 100) : 1); //If no percent-value is set, take the default value by multiply the value with 1.
      $item->weight *= (!empty($op_weight) ? ($op_weight / 100) : 1); //If no percent-value is set, take the default value by multiply the value with 1.

      $combination = array();
      foreach ((array)$item->data['attributes'] as $aid => $value)
      {
        if (is_numeric($value))
        {
          $attribute = uc_attribute_load($aid, $item->nid, 'product');
          if ($attribute && ($attribute->display == 1 || $attribute->display == 2))
          {
            $combination[$aid] = $value;
          }
        }
      }
     
      ksort($combination);

      $result = db_query("SELECT
          model
        FROM {uc_product_adjustments}
        WHERE nid = %d
        AND combination LIKE '%s'",
      $item->nid, serialize($combination));
     
      $model = db_result($result);

      if (!empty($model))
      {
        $item->model = $model;
      }
    break;
  }
}