Logitech Wireless Mice M525 (Green/Gold) for $14.90.  Order online for in-store pickup at Staples to lock in the price, ensure availability, and save on shipping.  Otherwise, shipping is $9.95 for a total of $24.85 shipped.  Here is a screenshot for your reference.  It features micro-precise scroll wheel, ergonomically shaped, three year battery life, Logitech Unifying receiver, Logitech Advanced 2.4 GHz wireless, and Logitech Advanced Optical Technology.  Most places have it for about $32.