Hi ank,
The most important part of the “value” of a mattress is how well it matches your specific needs and preferences in terms of PPP. Some of the options you are considering may work well for you and some may not depending on your body type and sleeping position and no matter what the cost or “value” of any mattress or the materials inside it, if it isn’t a good match for your body type and sleeping style in terms of PPP then it would have little value to you.
Once you have narrowed down your options at each store to one based on your testing … then the next step would be to find out the type and blend of the latex inside each one so you are comparing apples to apples. I believe that both of them use 100% natural Dunlop latex and if this was the case then they would be closely comparable in terms of the quality/durability of the latex but they may each have different covers and quilting which can make a significant difference both in terms of “feel” of the mattress and its cost. If the covers are also similar or the same then they would be closely comparable in terms of quality and value. I would also make sure that both are 100% natural Dunlop and you are not comparing organic Dunlop to 100% natural Dunlop (which are the same in terms of quality and performance but the organic certification adds to the cost of the material). You can read more about the different types of latex in post #6 here.
If two mattresses use the same type and blend of latex, are the same thickness, have a very similar cover, and are both suitable in terms of PPP … then the price and any of the other options that are part of the purchase that have “value” to you and are included in the purchase price (such as trial periods, return and exchange policies, a foundation, set up, removal of your old mattress, free pillows or mattress protector etc) would be the main factors in the value of each purchase relative to the other one. These are all part of each person’s personal value equation.
I’m not sure what you may be missing either (and it may just be that website purchases are a lower cost for the same mattress) but I do find their websites somewhat difficult to follow. I would call and talk to them to confirm the specifics of the layers in each specific mattress you are considering and have them explain any differences between them that account for any differences in the prices so you are clear on the materials and components in each one.
Once you know the specifics of all the materials in each of your “finalists” (at both stores) and you have tested them for PPP … then you will be in a much better position to make meaningful comparisons between them.
Phoenix