Hi jk,
Yes … ESW has since begun to make their own mattresses which are similar to the BE mattresses they used to carry (see post #4 here and post #9 in the same topic.
The raw material costs that a mattress manufacturer pays for their materials or all the other factors that are part of the final cost of a mattress isn’t something that you will be able to find out and isn’t really a meaningful way to compare mattresses anyway (see post #4 here). This type of “value comparison” will only take you down the rabbit hole into an endless number of finer and finer details and more intricate research without ending up with the more quantifiable answers you are looking for anyway (assuming you can even find out the detailed information you would need to know in the first place and then be willing to go through the learning curve involved to learn enough to be able to "translate it into meaningful terms). Just as one example, one mattress may have more wool and one may have less but the mattress with less may use a different breed which is more costly or has a different feel or performance or may have a organic certification that can also make it more costly. Cotton fabrics also have a wide range of price differences and different components that are similar (such as two different types of pocket coils or microcoils) may have a different “feel” or perform differently in combination with the other materials and components in a mattress and while they may also have a different cost, a manufacturer may choose to use one or the other because they produce a mattress that has a certain feel along with the other materials in the mattress that are closer to the design goals or target market of the mattress.
There is more about the most important parts of the “value” of a mattress purchase in post #13 here but it really boils down to #1 which is suitability (how well you will sleep on a mattress), #2 which is durability and how long you are likely to sleep well, and #3 which is all the other parts of your personal value equation that are most important to you.
All the mattresses at both ESW and Berkeley Ergonomics use high quality materials and none of them have any weak links in their design in terms of durability. The most important part of how they compare would be based on your own careful and objective testing for PPP (Posture and alignment, Pressure relief, and Personal preferences) is the most effective way to compare them.
With their mattresses that have a “similar” (but not the same) design and components it would be reasonable to consider them to be close equivalents in terms of durability even though they may feel and perform differently. Some of the other factors involved in the durability and useful life of a mattress relative to each person (see post #4 here and the posts it links to) will probably play a bigger role in the useful life of each mattress than any differences in the components they use.
I would treat any differences between them in the finer details of their materials and design as less important and would compare them based on all the objective, subjective, and intangible parts of your personal value equation that it’s possible to know or feel and that are most important to you.
Phoenix