Polk Audio via eBay offers its factory-refurbished Polk Audio Omni S2 Wireless Speaker, model no. AM6912-A, for $69.99 with free shipping. That's the lowest total price we've seen in any condition, plus it's $50 less than a new unit today. This compact speaker features a swappable white faceplate, two 2" full-range drivers, 2-channel amplifier, and built-in dual-band WiFi. A 6-month Polk Audio warranty applies.