Amazon has the TaoTronics 4K Waterproof Sports Action Camera for $47 with free shipping. Features capture Life at 4K 30fps, Wi-Fi, and iOS/Android compatibility, built-in rechargeable battery, comes with a protective waterproof case, a helmet mount, a bike mount.
Ends 6/30. Amazon has the Boocosa 720p Wireless IP Camera (wific168) for $50 - $25 off with coupon ISSMG824 = $25 with free shipping. Features 2-way audio, motion detection, pan/tilt, and remote viewing via smartphone app.
eBay has the GoPro Hero5 Session 4K Action Camera (CHDNH-B16)refurbished for $120 with free shipping. List price: $200. Features up to 4K video recording, 10MP photo resolution, micro SD slot and WiFi. It's waterproof up to 33 feet without a housing.