A:Answer The price is likely due to both the convenience of wireless, and the additional technology necessary to make a wireless mouse vs a wired one. As for the mouse button numbers: Left click= mouse 1, right click= mouse 2, scroll wheel click= mouse 3, the buttons by the thumb are 4-9 and I believe the + and - buttons by mouse 1 are 10 and 11, though I'm not 100% which is which. Likely - is mouse 10 and + is 11.