I'm done with inner spring mattresses. They don't hold up for sh1t. I'd really like to try one of those knock-off air beds. The bonus of those is that they will never sag or loose their shape. The padding on the top might but I'd get a bare one and add my own topper. The cheapest king I can find is about $1000. I can get a foam mattress for about $500 but they seem to get mixed reviews over long periods. Everyone loves them in the first month but a year down the road people don't like them as much.