Amazon offers its Prime members preorders of the Microsoft Xbox One Wireless Adapter for Windows, model no. HK9-00001, for $24.99 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it costs an extra $4.98.) That's the lowest total price we could find by $3. It allows you to play your Xbox One wireless controllers on Windows 10 PCs and tablets.
Note: This item is expected to ship November 3.