web scraping does not work only on this site

I'm using the same code to get the price of different web pages (7 in particular), all work perfect, but in 1 I can not get any data, could you tell me if it is impossible, if the page has any protection? Thanks in advance.

$source = file_get_contents("https://www.cyberpuerta.mx/Computo-Hardware/Discos-Duros-SSD-NAS/Discos-Duros-Internos-para-PC/Disco-Duro-Interno-Western-Digital-Caviar-Blue-3-5-1TB-SATA-III-6-Gbit-s-7200RPM-64MB-Cache.html");

preg_match("'<span class=\"priceText\">(.*?)</span>'", $source, $price);

echo $price[1];

I hope this result: $869.00

This code only works badly on the website shown in the code.