Sears offers the Beautyrest Recharge Grady Firm Tight-Top Mattress in King or California King for $733.49. Coupon code "SAVE50" cuts that to $683.49. With free shipping, that's $1,037 off and the lowest total price we could find. It features hundreds of individually-wrapped coils, an AirCool BeautyEdge foam encasement, GelTouch foam, and SurfaceCool fiber sleep surface.

Of note, Shop Your Way Rewards members will earn a Sears credit with this purchase and may be eligible for additional credits and discounts.