So I had a $3500 king koil mattress, after 3 years it was very uncomfortable however AH Beard would not replace. It had sagged and there were big saggs however not the 50mm required.
I have ordered 3 mattresses in a box, and today I finally cut up my old $3500 mattress to find what it was made from.
1/2 cm thick memory foam
3cm of two different cheap foams
Then pocket sprung base.
What I really noticed is how cheaply it was put together, I cut the first bit, but then it was very easy just to rip it. It was glues together (badly) and the springs look like a poor grade steel.
What a rip off.
Other mattresses could be bought for much less with almost the same (or better) components.
I will take some photo's but feel free to ask me anything.