For a limited time, this Spa Sensations 6'' Memory Foam Mattress drops to as low as $99 for Twin at Walmart.com. Other sizes also drop in price, such as $119 to $109 for Twin XL, $129 to $119 for Full, $159 to $139 for Queen and $179 to $159 for King. These also ship for free or can be picked up at your local store (where available). This features a full support with high-density base layer and has been rated 4.3 out of 5 stars (from over 2600 reviewers)! Sales tax is charged in most states.