Apple Store offers the fatory-refurbished Apple AirPort Extreme 802.11ac Wireless Base Station, model no. ME918LL/A, for $129 with free shipping. That's the lowest total price we could find for a refurbished model with an Apple warranty by $21, although we saw a refurb for $19 less last fall. It uses 802.11ac WiFi technology, which offers up to 40% faster transmissions than 802.11n. A 1-year Apple warranty applies.