Newegg via eBay offers the refurbished Logitech Z323 2.1-Channel Speaker System in Black, model no. 980-000354, for $19.99 with free shipping. That's $5 under our March mention, the lowest total price we've seen, and the best deal today by $14. Features include 30 watts RMS of total system power, two satellite speakers, a subwoofer, 40Hz to 20kHz frequency response, RCA audio and 3.5mm inputs, and headphone jack.
Note: A 90-day warranty is included, but it's unclear who backs it.