Akaso Action Camera - $40 (Temple)

Fully functional! Includes the camera, a waterproof case, 2 batteries, a battery charger, and a 32gb micro SD card.
Used this on my fire helmet, but I don't use it enough to justify having it and could use the money for better things.
Records at 720p 120 (slomo), 720p 60, 1080p 60, & 4k 30.
I can provide a video I filmed with it.