This deal has ended.
Overstock drops the Slumber Solutions Highloft Supreme 4" Mattress Foam Topper from $74.99 to $67.49. With $1 shipping, that is the lowest total price we could find and one of the least expensive 4" toppers we've seen to date. It's available in sizes from Twin to California King for this same price and it is well reviewed with 4.5 out of 5 stars from over 590 buyers. There is no sales tax (except UT).