Akodi via Amazon offers the Anewkodi AC600 Dual-Band 802.11ac Wireless USB Adapter for $17.99. Coupon code "Q45BE7SE" cuts that to $9.99. Plus, Prime members receive free shipping. That's the lowest price we could find for such an adapter shipped from the U.S. by a buck. It features a long-range 2dBi antenna and up to 600Mb/s WiFi speeds on 5GHz and 2.4GHz bands. Deal ends October 15.

Don't need it soon? Focus Shopping via eBay offers a similar unit for $8.66 with free shipping. It ships from Hong Kong and may take up to four weeks to arrive.