markdown-madness via eBay Daily Deal offers the Microsoft Wireless Mobile Mouse 3500 2-Pack, model no. GMF-00017, for $19.99. With free shipping, that's $20 under the lowest total price we could for this quantity. (We saw this item sold individually for the same unit price three weeks ago.) This wireless mouse features BlueTrack technology (which purportedly works on more surfaces than optical or laser technology), a nano transceiver, on/off switch, and more.