Newegg offers the Microsoft Desktop 800 Wireless Keyboard and Mouse, model no. 2LF-00001, for $19.99 with free shipping. (Amazon has it for the same price for Prime members.) That's tied with our July mention and the lowest total price we could find by $5. This set features a wireless range of up to 30 feet; the keyboard includes hot keys and the mouse has 1,000 dpi.
newegg offers the Rosewill 2.4GHz Wireless Optical Mouse with Nano Receiver, model no. RM-7700, for $7.99 with free shipping. That's the lowest total price we could find by $4, although it was $2 less in June. It features automatic standby mode, ambidextrous design, and ergonomic shape.