The memory foam got softer and left a silhouette where you would lay down after about 5-6 years.

The sleep number bed was just over $4,000 for the Sleep Number 9000 Bed in Cal-King. Be sure to do your homework though because the reviews are mixed. Some people had trouble with air leaks and other quality issues. Ours is wonderful and I suspect the poor reviews are mainly for the entry model which I did not like in the least bit.