This deal has ended.
Update: this is now back to $40. The Logitech MX518 Optical Gaming Mouse is now at Newegg for $34.99, the lowest price around. I use this mouse (not for gaming but for everyday tasks) and love it. It features eight buttons, up to 1600 dpi scrolling, comes with three-year warranty, and connects via USB. Shipping is free and there is no sales tax (except CA, TN, NJ).