NeweggFlash offers the refurbished Linksys N600 Pro 802.11n Wireless Dual-Band Range Extender, model no. RE4000W, for $19.95 with free shipping. That's $5 under the lowest total price we could find for another refurb and the lowest total price we've seen. It simultaneously extends ranges for 2.4GHz and 5GHz bands. Features include up to 600Mbps data rates, two Ethernet ports, and WEP, WPA, WPA2, or WPS security. Deal ends August 24.
A 90-day warranty applies, but it's unclear who back it.