Hi Stevegrossie,
The closer to the top of a mattress a layer is … the more mechanical stress it is subject to and the more durability of material becomes an issue. In the case of the Peace … the top 2" is latex which means the most durable material is on the top which is good but then the rest of the comfort layer and the support layer below it is polyfoam. In the case of polyfoam … the denser the foam … the more durable it will be. The best quality polyfoam approaches latex in its durability but this is rare to see in most mattresses. Typically support layers are in the range of 1.8 lb and higher which generally work well in terms of durability (as a reference … tempurpedic for example is about 2.2 lbs). Softer polyfoams are also less durable than firmer polyfoams as they are also subject to more mechanical stress. I would want to know the density of the polyfoam in the comfort layers in the mattress because this will play a bigger role in its durability than the polyfoam in the support core.
The tradeoff of course is that the more latex there is to replace polyfoam … the more expensive the mattress will be.
There are some good San Francisco options in Post #2 here in case you haven’t seen them which have some very good value and would be well worth including in your research.
$1600 is “on the low side” for most all latex king size mattresses but of course this depends on the thickness of the mattress, the type of latex, the ticking/quilting, the overall mattress construction and layering as well as the differences between different outlets.
Latex mattress that use a latex comfort layer over good quality polyfoam or innersprings can be a very good option either for those who prefer an innerspring feel or for those who are looking for the benefits of latex in the comfort layer but don’t have the budget for a latex support core.
The Ikea Sultan Edsele is 85% natural latex using continuous pour Dunlop. While this isn’t the same quality as molded 6" cores from other Dunlop sources … it’s certainly better quality than Dunlop blends that have a higher SBR (synthetic latex) content and it has good value. It may be necessary for many people to add a topper to this as it would be quite firm by most standards.
Overall I would probably take some time on the phone with some of the San Francisco outlets I listed earlier and talk with them about their options and pricing. There are some very good choices there. While they are a ways from San Francisco … I would certainly include Bay Bed in your phone research. They are a member of this site and may well be worth the drive.
Phoenix