iNetworkTech via eBay offers the TP-Link 802.11n Wireless Dual Band USB 3.0 Adapter, model no. N900, for $14.99 with free shipping. That's the lowest total price we could find by $15. It provides up to 900Mbps WiFi speeds with simultaneous 5GHz (450Mbps) and 2.4GHz (450Mbps) bands.