Amazon offers Prime members the Kikkerland Log Pillow Micro Bead Head Cushion for $8.85 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $6.83.) That's $1 under our mention from two weeks ago and the lowest total price we've seen. (It's a current low by a buck.) It measures 15" x 6.5" x 6.5".
Of note, 13 Deals offers a generic one for $8.49 with free shipping.