Best Buy via eBay offers the Logitech M570 Wireless Trackball in Gray/Blue, model no. 910-001799, for $29.99 with free shipping. (Amazon offers it to Prime members for the same price.) That's tied with our May mention and the lowest total price we could find by $4. Features include programmable buttons, 2.4GHz wireless, and up to 18 months of battery life. Coupon expires after 100 uses.

Also available is the Logitech Z313 2.1-Channel Speaker System in Black/Silver, model no. 980-000382, for $29.99 with free shipping. That's tied with our March mention and the lowest total price we could find by $5. It features 25 watts RMS of total system power, two satellite speakers, a subwoofer, wired remote, and headphone jack.