Hi Nosila S.
European sleep works sells Berkeley Ergonomic mattresses which I think highly of and are good quality and value choices. A forum search on Berkeley Ergonomics (you can just click this) will bring up much more information about them along with feedback from others who have purchased them.
Once you begin adding foam or even just latex foam to the innerspring and natural fiber combinations you are considering your options become much larger and there may be more mattresses with better “value” for you to test in person in most areas of the country.
I don’t think anyone can answer this for someone else because each person may have a different “personal value equation”, be more or less familiar with different material combinations that are similar, or have a greater or lesser risk tolerance for making a mistake. Some people also seem to be able to sleep on anything whether they are familiar with the materials or design or not and for those they could probably just throw a dart at a group of pictures and make what for them would probably be a good choice but would be a disaster for someone else.
Most of us are not so fortunate though and need to pay a little more attention to matching our individual needs and preferences (or to quality and value) and I think my answer to you would be the same as post #3 here from last night which asked a similar question and which outlines the pros and cons of each.
Phoenix