Rush Hour Wholesaler via eBay offers the open-box Microsoft Xbox 360 Wireless Game Controller in Black, model no. NSF-00001, for $19.99 with free shipping. That's $1 under our open-box mention from last June and the lowest total price we've seen for this controller in any condition. (It's also $3 under the best price we could find for a new one today.) This 2.4GHz wireless controller features a 30-foot range, 40 hours of life with two AA batteries (included), and 2.5mm headset jack.
Note that this item ships in bulk packaging.