Sears offers the Sunham Memory Foam Windowpane Bath Mat in six colors (Ivory pictured) for $9.99. Opt for in-store pickup to avoid the $5.75 shipping charge. That's $10 off list and the lowest total price we could find. It measures 17" x 24".
It's also available in a larger size of 21" x 34" for $14.99 with the same pickup option as above. That's also $10 off and the best we could find. Of note, Shop Your Way Rewards members will earn a Sears credit with this purchase and may be eligible for additional credits and discounts.