Newegg offers the Sony 3-Speaker Home Theatre Upgrade Package, model no. SS-CR3000, for $49.99 with free shipping. (Amazon offers it for the same price.) That's tied with our mention from three weeks ago as the lowest total price we've seen. (It's also a current price low by $48.) These three speakers (one center speaker and two rear speakers) are meant to add on to an existing 2.1-channel system for 5.1-channel surround sound.
Note: If you haven't yet, use Newegg's smartphone app or Newegg's mobile site and apply coupon code "MBLNBF14R2B" to cut it further to $47.49. (This discount can only be used once per account.) Deal ends today at 11 pm ET.