While some mattress brands (such as Helix and Saatva) don't offer clearance or close-out sales, a lot of popular mattress brands do. For instance, US bed-in-a-box brand Casper has a clearance ...

It's end-of-year clearance sale season ... is functionally a platform bed frame, with wooden slats supporting the mattress and eliminating the need for a box spring. These slats can be lifted ...