This deal has ended.
Overstock drops the Serta Ultimate 4" Memory Foam Mattress Topper from $189.99 to $134.99. Plus, new customers get 5% off via this link, making the price $128.20. With $1 shipping, that's the lowest price we could find for the topper by $60! It is available in twin, full, queen, king, or California king for this price. There is no sales tax (except UT).