Newegg offers the refurbished Logitech M570 Wireless Trackball, model no. 910-001799, for $29.99. Coupon code "EMCWWPH23" cuts it to $24.99. With free shipping, that's $3 below our January mention and $5 under the lowest total price we could find for a refurb elsewhere. Features include programmable buttons, USB 2.0 receiver, 2.4GHz wireless, and up to 18 months of battery life. Deal ends November 26.
Note: No warranty information is provided.