Hi BeanBean,
This is a very complex question because it is one part of many variables involved in mattress design theory which makes one mattress suitable for one person and not another. Just to give one single example … if you have a mattress that uses the same type, thickness, and firmness of support core then for some people a 3" latex comfort layer with a particular type and firmness of latex with a particular cover may be a perfect “match” in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) and for someone else they may do best with a thicker or thinner comfort layer or a different firmness level depending on their body type, sleeping style, or preferences. Even changing the type or firmness or thickness of the support core can mean that a different comfort layer (in terms of firmness or thickness) may be necessary for a mattress to be the best possible “match” for a particular person. There are many interacting variables in other words.
In very general terms though … there is more about the pros and cons of a latex hybrid vs an all latex mattress in post #2 here and more about the Aloe Alexis vs a mattress with less latex in the upper layers in post #2 here that it links to. A mattress with thicker or multiple layers of latex over a polyfoam support core (such as the Aloe Alexis) would be closer “as a whole” to the feel and performance of “all latex” than a mattress that used thinner comfort layers over a polyfoam core. In very general terms … the more latex there is in the upper layers the more the mattress will have the feel and performance of latex and thinner or softer layers of latex in the top layers will result in more of the feel and performance of the polyfoam support core below it to “come through”.
With thinner layers of latex on top of a mattress then the density of the support core would also play a more significant role in the durability and useful life of a mattress and this can be more important with higher weights because heavier body types (or those where weight is more concentrated in one part of the body) will compress the deeper layers more than lighter body types.
The Cotton Camilla uses a lower density support core than either the Bamboo Bliss or the Aloe Alexis so this would be a more important durability factor for those in higher weight ranges. The Aloe Alexis would be more durable yet for higher weights especially because of the extra layer of latex so the layers that are most compressed when you sleep on the mattress would be the latex which is more durable even than higher quality/density polyfoam. Besides being closer to the feel of an all latex mattress … the extra layer of latex in the Aloe Alexis also provides more options to fine tune the mattress because you would have the option to either rearrange the layers or exchange either one of the layers rather than just one.
There is also more information that compares the Cotton Camilla and the Bamboo Bliss (and the Dreamfoam Eurotop) in post #16 here.
All the mattresses that are made by the same manufacturer would be in a similar “value” range based on the cost of materials (although higher budget mattresses may have a slightly higher margin) but there is much more involved in assessing the “value” of a mattress purchase than the raw material cost of a mattress, the price per inch of latex, or the cost per pound or yard of fabric or natural fibers. There is more about the most important parts of the “value” of a mattress purchase in post #13 here that can also help you compare the “value” of different mattresses based on the criteria that are most important to you. If in hindsight you would have the same quality of sleep on two different mattresses and they were equally durable then I would agree with you that there would be little benefit to paying more but this can only be known in hindsight and it’s much more difficult to predict this without being able to sleep on both mattresses before you buy one of them so when you can’t try a mattress in person (or a mattress that is virtually identical) then “best judgement” based on more detailed conversations with a knowledgeable and experienced manufacturer so they can “talk you through” the pros and cons of the options they have available is the best way to decide which mattress would be “best for you” regardless of whether someone else may make the same choice.
@ davidm,
Hopefully this will help with your questions as well 
Phoenix