TigerDirect offers the Logitech Clip-On Speaker for Apple iPad, model no. 984-000193, for $19.97 plus $2.29 for shipping. Outside of the price below, that's the lowest total price we could find by $3. This speaker features a rubberized clip that attaches securely to your Apple iPad or other tablet with a 3.5mm audio output.

A close price: Logitech sells a "dented box" version for $19.99 before coupon code "logi_tabs_52512", $17.99 after. Shipping adds $6.21. Coupon expires today.