Hi valleyrose,
You can read more of my thoughts about Saatva in post #1 here and a forum search on Saatva (you can just click the link) will bring up much more information and feedback about them as well.
There is more about the most important parts of the “value” of a mattress purchase which is relative to the criteria that each person may have in post #13 here but overall … I would say they would be in a “better than average” quality/value range compared to most mainstream choices but not in the “best” quality/value range for most of the people that are members of this site who are much more familiar with all the other options (online and locally) that are available to them.
Just in case you haven’t read it yet … I would start with the mattress shopping tutorial here which has all the basic information, steps, and guidelines that can help you make the best possible choices … and know how and why to avoid the worst ones.
Phoenix