TRENDnet 300Mbps Wireless-N (802.11n) Easy-N-Upgrader for $25.60 Shipped

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.