Sam's Club has Serta king size mattresses on sale for $598 and the boxspring is $198 plus you get a $50 gift card immediately. I don't know how long this offer will last but I got it last night. The $50 gift card is given to you right when you purchase. This was by far the cheapest place to find a name brand mattress as I have done plenty of research online and in furniture stores in my area. Enjoy!!!!