A few months ago I got an Anker vertical mouse on Amazon, I think around $15. I'm really liking it so far. I never had much of wrist pain, but the position does feel more natural to me.
If I had an improvement to the vertical mouse, it might be a joystick type shape (still moving across a desk, not an actual joystick), but without trying it out it would be hard to know how well it works.
Overall I like the inward movements and natural rest position. It was cheap to try out, but I won't be going back to a regular mouse for office use.
