Hi kws87,
This is a reference post which is always kept up to date as new information comes to light. It was last updated on July 9th, 2014.
Unfortunately I don’t have the time to go through all their websites and make price or “value” comparisons (and price is only one part of the “value” of a mattress … see post #13 here) and this is the part of your research that you will need to do on your own.
All of the online retailers and manufacturers in the list are completely transparent about all the materials in their mattresses (which is one of the reasons I included them) and will provide you with any of the information you need when you talk with them about any of their mattresses.
Phoenix