If the only place I ever bought something was Amazon how do I know if the charger was "half price?" Especially if you didn't know counterfeit chargers were a th

If the only place I ever bought something was Amazon how do I know if the charger was "half price?" Especially if you didn't know counterfeit chargers were a thing? These chargers are some of the best selling products on Amazon's charger category. In most cases they outsell the genuine versions.