Mattresses may be marketed for a long life span but they rarely last that long. I've had a queen size $3k mattress that lasted 8 years. Bought a $1.5k replacement that lasted 1.25 years before it had noticeable body impressions. Mattressfirm replaced it in warranty. A $2k mattress at 4 years is $1.38 per day. You won't notice a mattress is destroying your back until it's too late.