Walmart offers the Remedy Natural Pedic Memory Foam Wedge Pillow for $22.49. Opt for in-store pickup to dodge the $5.99 shipping charge. (Amazon charges the same with free shipping for Prime members, although it may take up to three months to ship.) That's the lowest price we could find by $4. It's designed to elevate the head and open up the breathing passages.
A close price: Home Depot charges $23.16 with free store pickup.