Cheapest I've seen new since the Amazon deal of £16.13 on September the 10th last year.
Blurb: With the Xbox Wireless Adapter, experience the advanced precision and comfort of your Xbox Wireless Controller on Windows 10 PCs, laptops, and tablets. Use it with PC games, and Xbox One games streamed to Windows 10, to elevate your game wherever you want to play.
1 x Xbox Wireless Adapter for Windows 10
1 x USB Extension Cable