Price Doesn't Appear In Description

Please help!

I'm trying to generate description and I want to add price there

Here's the code

if ($mode == 'view' && !empty($_REQUEST['product_id'])) {
$product = Registry::get('view')->getTemplateVars('product');
if(empty($product['meta_description'])){
//other data can be added to title dynamic also
$meta_description = $product['product'];
Registry::get('view')->assign('meta_description', "Купить " .strtolower($meta_description) ." за " .$price ." р. " ."от производителя" .$brand ." на маркетплейсе. Доставляем по всей России!");
}
}
But price doesn't appear and so does brand
Thanks in advance!

You should try

$product['price']

instead of

$price