A convenient way to create and manage feed files is to use RetailTower's platform. They support many popular eCommerce Platforms such as Magento, Shopify, osCommerce and Big Commerce (ZenCart and 3DCart coming soon!).
PriceMe is a RetailTower partner. You can sign-up here and generate your PriceMe feed file (select PriceMe as your target after sign-up).
You could use RetailTower to generate feed files for many popular shopping sites, not only PriceMe.