ELI5 Mattresses - what makes them so expensive?

ELI5 Explain Like I'm 5: Bite sized answers to stuff you should know about - in a mini podcast

What makes mattresses so expensive? What is the purpose of a box spring underneath? What is the best way and optimal position for humans to sleep? Why do we humans like to use a pillow to support our heads when we sleep?

... We explain like i'm five!

Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: musical_jinn, crackyospine, shakeanjake, epicjigsaw, nittygrittytruth and andy_clark

To the ELI5 community that has supported us so far, thanks for all your feedback and comments. Join us on Twitter:

https://www.twitter.com/eli5ThePodcast/

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