Нули где нет цены - [VM2&3] Общие вопросы и ошибки

<meta itemprop="price" content="<?php echo $this->product->prices['product_price'];?>">

print_r($this->product->prices); 

Array 
( 
[product_price] => 
[virtuemart_product_price_id] => 0 
[product_currency] => 
[price_quantity_start] => 
[price_quantity_end] => 
[product_price_publish_up] => 
[product_price_publish_down] => 
[product_tax_id] => 0 
[product_discount_id] => 
[product_override_price] => 
[override] =>
[categories] => Array 
 ( 
 ) 
 [shoppergroups] => Array 
 ( 
 ) 
[virtuemart_shoppergroup_id] => 
[costPrice] => 
[basePrice] => 0 
[basePriceVariant] => 
[basePriceWithTax] => 
[discountedPriceWithoutTax] => 
[priceBeforeTax] => 
[taxAmount] => 
[salesPriceWithDiscount] => 
[salesPriceTemp] => 
[salesPrice] => 
[discountAmount] => 
[priceWithoutTax] => 
[variantModification] => 
[unitPrice] => 
)