Best Buy has the GoPro HERO5 Black 4K Action Camera (CHDHX-501) for $400 with free shipping. Features capture high-quality 4K video, 2" color touch-screen LCD display, electronic image stabilizer, microSD card slot, built in Wi-fi and Bluetooth, includes curved + flat adhesive mounts, mounting buckle, rechargeable battery, USB-C Cable.
GearBest has the V3 4K WiFi Sport Camera for $34 with free shipping. List price: $60. Features adopts Allwinner V3 chipset, with IMX179 CMOS sensor, for shooting high-quality images, 16MP photo resolution, video resolution: 4K 30fps, 2.7K 30fps, 1080P 60fps, 1080P 30fps, 720P 90fps, 720P 60fps, 720P 30fps, 170° wide-angle fish-eye lens.
Amazon has the Best Vision SK-DVR-DIY-16 16-Channel D1 DVR Security System + 8 800TVL IR Outdoor Weatherproof Bullet Cameras for $250 with free shipping. List price: $500. Includes a 1TB HDD and 8 IR night vision camera with motion detection.
Has excellent Amazon Reviews.