TRENDnet 300Mbps Wireless Easy-N-Upgrader for $24.99. Here is a screenshot for your reference. Add a filler such as this for $0.61 to get free shipping so the total is $25.60 shipped (or combine it with other Amazon deals). Note that this is not a router itself but is more like an access point. It gives the advantage of not having to reconfigure the network while adding 802.11n (300Mbps) to a wireless network. Most places sell this for over $55.