I just picked up the mx revolution at Best Buy last week for $40, really great mouse, works fine.
Best Buy had it in their ad the week of Dec 27-Jan 2. They advertised $60 off. I suspect that Logitech is coming out with a new mouse, as this one has been out for couple of years, and they are trying to blow out their inventory. The majority of the time, I find much better deals on the internet than I ever do at Best Buy, but not this time.