Best Buy offers the Logitech Wireless Performance Mouse MX, model no. 910-001105, for $44.99 with free shipping. (Amazon charges the same.) That's $5 under our mention from last month and tied as the lowest total price we've seen for a new one. (It's also a current price low by $12.) It features four thumb buttons, scroll wheel, and Logitech unifying receiver dongle that allows the addition of a compatible wireless keyboard without multiple USB receivers.