Yi Technology via Amazon offers the Yi Home 720p WiFi Security Camera 4-Pack for $139.99. Coupon code "YCPCR8QY" cuts that to $114.99. With free shipping, that's $25 under the lowest price we could find for this quantity elsewhere. (For further comparison, we saw a single camera for $30 last month.) Each camera features 720p recording at 20fps, a 111° wide-angle lens, 802.11n wireless, and 2-way audio.