Hi Justin42284,
Once you have eliminated the worst choices and narrowed things down to final choices between “good and good” … then there really isn’t any “best value” any more except based on your own “personal value equation” which includes all the objective, subjective, and intangible parts of a mattress purchase that are most important to you.
I think though that you may still have some eliminating to do.
One of the most essential parts of your research would be to talk with each of the manufacturers or retailers that you are considering on the phone so you can have a more detailed conversation to find out how knowledgeable they are about mattresses and materials and have some reasonable assurance that a mattress you are considering would be suitable for your needs and preferences. No matter what the quality or value of a mattress if it’s not suitable for your body type and sleeping style then you won’t be able to sleep on it and it would have little value to you and the cost of returning it could be close to the cost of the mattress. You could also ask them about all the specs you need to make an informed decision. I would never buy a mattress online without talking with a knowledgeable and experienced person that I trusted would give me good information about their mattress and who was more interested in helping me make the most suitable choice than they were in making the sale.
Memory foam and latex are very different materials and I would first do enough local testing on each material to decide which of them you prefer as that will help you narrow down your options. If you choose a material that you don’t like then once again the mattress may have little value to you.
I would also spend enough time on the phone with each retailer or manufacturer to narrow down your choices to the one they offer that you would choose out of the options they have available so your final choices include what you believe is the “best” option from each one.
A few other comments …
These types of “spec” questions are best asked of the manufacturer or retailer themselves to make sure the information you receive is accurate but in this case I believe it’s 1.5 lb.
I would avoid Dynasty mattress (see post #4 here and the posts it links to). Their specs are not likely to be correct and they don’t meet the criteria I would use for buying a mattress that was made in China (besides their inaccurate listing they are not CertiPur certified). NOTE: they have since been listed on the CertiPur site.
Also 1.5 lbs.
You can see my comments about this mattress in post #4 here.
This is another one I would avoid because it doesn’t meet the criteria I use for memory foam mattresses. They are also quite “loose” with their descriptions. Did you also notice the picture that contains 14" of foam for a 12" mattress? As you can see here as well their specs don’t add up and this one also has specs that don’t add up either. They also aren’t CertiPur certified.
As you mentioned this one has 2" of 3 lb memory foam which would be enough for me to rule it out as well.
When you are dealing with online merchants … and especially if you haven’t talked with them in person to find out how knowledgeable they are … it really is buyer beware.
Phoenix