Newegg offers the TP-Link N300 802.11n Wireless Range Extender, model no. TL-WA855RE, for $12.99 with free shipping. (Amazon charges the same for Prime members.) That's $2 under our September mention and the lowest total price we've seen. (It's the best deal now by $5.) This 802.11n wireless range extender expands coverage via a push of the range extender button.
Update: It's now sold out at Newegg; however, Amazon still offers it for $12.99 with free shipping for Prime members.