Groupon offers the factory-refurbished 4.4-lb. Acer CB3-531-C4A5 Intel Celeron 2.16GHz 15.6" Chromebook, model no. NX.G15AA.001, for $109.99 with free shipping. That's $88 off list and the lowest total price we've seen for this system since April, when we saw a refurb for an all-time low of $103. It features an Intel Celeron N2830 2.1GHz Bay Trail dual-core processor, 15.6" 1366x768 display, 2GB RAM, 16GB internal storage, 802.11ac wireless, Bluetooth 4.0, USB 3.0, HDMI, 4-cell battery, and Chrome OS. A 90-day Acer warranty applies. Deal ends October 15.