As part of their Red Line Deals, Overstock drops the price of the Serta Rejuvenator 4-inch Memory Foam Mattress Topper from $157.99 to $84.99. With $2.95 shipping, that's $5 less than our January mention and the lowest price we've seen this year. This topper is available in five different sizes for this same price and has a 2.5-inch base layer and a 1.5-inch temperature-sensitive top layer. It is well reviewed with 4.5 out of 5 stars from over 3,480 buyers. There is no sales tax (except UT).