eBay has the Harman Kardon HKTS 15 5.1 Home Theater Speaker System for $150 with free shipping. Retail price: $649. Features 35Hz - 20kHz frequency response (-6dB), 8 ohm nominal impedence, 86dB at 1W,10" woofer, center channel has dual 3" drivers.
Amazon has the Anker 20W Premium Stereo Bluetooth Portable Speaker (A3143011) for $45 with free shipping. Retail price: $120. Has excellent Amazon Reviews.
Amazon has the NHT SuperZero 2.1 Mini-Monitor Speaker (Single, Gloss Black) for $69 with free shipping. Retail price: $120. Has excellent Amazon Reviews.
Amazon has the Sonos Play:5 Wireless Speaker (Black) for $499 - $100 off with coupon SONOSPLAY5 = $399 (You must have an Alexa-enabled account to get this deal.) with free shipping. Features six drivers with dedicated amplifiers, Trueplay room tuning, Internet music streaming (such as Spotify, Pandora, or iHeartRadio).
Has excellent Amazon Reviews.