My ikea mattress (double, around £300) is already sagging after 18 months. I need a hard mattress (hard as possible - like a firm surface) to replace it with but no ideas which are reasonable and will last unlike the current one.
Recommendations welcomed. Open minded about orthopedic mattresses too.
My budget is up to about £350.
Saw some on Muji website that said they are very firm but no idea if they are any good. (?) other suggestions very welcome.
Many thanks!