Вывод курса валют в админке - Общие вопросы и ошибки

<?php echo "Курс ".$row->currency_id[currency_value];?>

<?php echo "Курс ".$this->currency_value;?>

$row1=$this->currency;
echo "Курс ".$row1->currency_value;
/*или другой */
$row1=$row->currency_id;
echo "Курс ".$row1->currency_value;

$currencies = $this->lists['currency'];
$count = count($currencies);
foreach($currencies as $currency){
	if ($row->currency_id == $currency->currency_id)
		$rez = $currency->currency_value;
	}		 
echo "Курс ".$rez;

$currency_id = $row->currency_id;
$currency = JSFactory::getTable('currency', 'jshop');
$currency->load($currency_id);
$currency_value = $currency->currency_value;
echo "Курс валют ".$currency_value;

$product = JSFactory::getTable('product', 'jshop');
$product->set("product_buy_price", $product_buy_price);

$db =& JFactory::getDBO();
$query = "UPDATE #__jshopping_products SET product_buy_price =". $product_buy_price." WHERE product_id =".$row->product_id."";
$db->setQuery( $query );
$db->query();