Microsoft Sculpt Comfort Mouse - $27.81
In Windows 10, you use the Start area a lot. That’s where you pin your favorite apps and open Settings. Get to Start faster with the Microsoft Sculpt Comfort Mouse.
The Microsoft Sculpt Comfort Mouse has a touch-sensitive Windows button where your thumb sits. Forget tapping on your screen or stopping what you’re doing to click on the Start button, with this mouse, it’s available to you instantly. Free software lets you change what the button does if you have other priorities. A dimple to the button's right provides a comfortable place to rest your lower thumb.
The Sculpt Comfort comes with two AA batteries that last for 10 months. Swap them for any other AA batteries once they die.
Amazon sells the Sculpt Comfort for $27.81.