Hi DanandKel,
The first place to start your research (if you haven’t already) is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and know how and why to avoid the worst ones.
Post #2 here has more information about safe, natural, organic, “chemical free”, and green mattresses and mattress materials that can help you sort through some of the marketing information and terminology that you will encounter in the industry that can help you differentiate between them and decide on the types of materials you are most comfortable having in your mattress and help you answer “how safe is safe enough for me”.
There is also more about the most important parts of the “value” of a mattress purchase in post #13 here and there is also more about the different ways to choose a mattress (online or local) and how to minimize the risks involved with each of them in post #2 here.
You can read more about the 12 in 1 customizable mattress mattress in this topic and in post #2 here. It uses high quality materials (2 lb polyfoam) and has many options to customize the firmness of the comfort and support layers. The polyfoam is CertiPUR certified and is a “safe” material but I would keep in mind that polyfoam isn’t a natural or an organic material if that is an important criteria for your wife.
While this mattress uses good quality materials … (2" of 100% natural latex over a 1.8 lb polyfoam support core) and there are no weak links in the design … it’s not likely that Overstock will be able to provide you with good guidance about whether the mattress would be a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) because they aren’t particularly knowledgeable about mattresses. They also only have one firmness option available and they have no return or exchange policy for mattresses once you have opened the packaging so this would be a very high risk purchase and if the mattress wasn’t a good match for you and you couldn’t sleep well on it then you wouldn’t have any options available to you and would be “stuck” with a mattress that you couldn’t use. The latex in this mattress is 100% natural but not organic and the polyfoam is a synthetic material (they don’t mention whether it is CertiPUR certified).
Their description of this mattress doesn’t provide the information you would need to make a fully informed choice (see this article). If you are able to find out all the specs and can confirm that there aren’t any weak links in the materials … then my comments about the previous mattress would apply here as well. The latex in this mattress would be a mostly synthetic latex blend but I would also keep in mind that memory foam and latex are completely different materials so I would make sure that you are clear about which type of materials you tend to prefer. There is more about memory foam vs latex in post #2 here. I would also avoid memory foam in any mattress that is being used by an infant (see post #2 here)
I would also keep in mind that memory foam and polyfoam (and the latex in this case) are synthetic materials so they may not fit your wife’s criteria for natural or “organic” materials".
Posts #3 here and #4 here also include some links to some of the lower budget latex and latex hybrid mattresses I’m aware of that may be helpful if you know that you prefer the feel and performance of latex and if you let me know your city or zip code I’d be happy to let you know about any of the better local options or possibilities I’m aware of as well.
Phoenix