Crown Comfort 12-inch Premium Memory Foam Mattress and Bi-Fold Box Spring Set-King Price:  $639.99 (as of 19/10/2017 00:33 PST- Details)

Amazing comfort from body-conforming
Feels like you are floating on a cloud
7″ Legs, what you can attach to box spring, are included so you don’t need to install other bed frame.