This Wireless-N router from Linksys aka Cisco seems rather cheap especially if you want to upgrade from a b/g to N
The Wireless-N Home Router is really three devices in one box. First, there's the Wireless Access Point, which lets you connect to the network without wires. There's also a built-in 4-port full-duplex 10/100 Switch to connect your wired-Ethernet devices together. Finally, the Router function ties it all together and lets your whole network share a high-speed cable or DSL Internet connection. The Access Point built into the Router uses the very latest wireless networking technology: Wireless-N (draft 802.11n). By overlaying the signals of multiple radios, Wireless-N's Multiple In, Multiple Out (MIMO) technology multiplies the effective data rate. Unlike ordinary wireless networking technologies that are confused by signal reflections, MIMO actually uses these reflections to increase the range and reduce dead spots in the wireless coverage area. The robust signal travels farther, maintaining wireless connections up to 3 times farther than standard Wireless-G.