Hi kmark,
If you do decide to go in that direction the tutorial post includes links to some of the better online options I’m aware of.
If you are looking locally then I would first narrow down your choices to the finalist at each retailer you are dealing with and making sure that you know the specifics of the materials and components in each mattress you are considering (see this article and the information in post #4 here) so you can identify any weak links in a mattress and make more meaningful comparisons between them.
The most important part of the “value” of a mattress purchase would be how well it matches your specific needs and preferences in terms of PPP based on careful and objective testing. This is the part that only you can decide because nobody else can feel what you feel on a mattress. No matter what the cost of a mattress or the quality of the materials … if you don’t sleep well on it then it would have little value to you.
If a mattress is a good “match” for you in terms of PPP … then the next most important part of the “value” of a mattress purchase is the quality of the materials so you can make sure there are no lower quality materials or weak links in the mattress and make more meaningful comparisons to other mattresses. You can’t “feel” the quality or durability of the materials. If a mattress is a great match for you in terms of PPP but it uses lower quality materials that will soften or break down too quickly relative to the price you paid then it would also have little value to you.
After the suitability of a mattress and durability based on the type and quality of the materials … the other parts of your personal value equation that are most important to you (including the price and any return or exchange options) would also be important parts of the “value” of a mattress purchase.
At Original Mattress Factory the Serenity Latex and the Serenity Plush all use good quality materials and there are no weak links in either mattress but which one is best for you would depend on whether you preferred to sleep on memory foam or latex and this is a personal preference. There is more about the new Serenity latex mattresses in post #3 here and post #2 here and post #7 here. there is also more about the Serenity memory foam mattresses in this thread.
I don’t know the specific layering or foam densities of the two mattresses you listed in the Orthopedic line so I can’t make any meaningful comments about them but if you can list the specs of the mattress I’d be happy to make some comments about the quality of the materials inside them or help you identify any potential weak links in their design.
The Healthy Back Elegance uses blended Talalay latex from top to bottom which is a good quality material so there are no obvious weak links in this mattress either although it’s in a higher budget range than other mattresses that use the same material.
The Healthy Back Embrace Relaxation also doesn’t include any information about the quality/density of the foam inside it so I would need more specifics to make any meaningful comments about it as well.
The first step I would take is to decide on whether you prefer sleeping on memory foam or latex (you can see some of the pros and cons of each in post #2 here) which would be the first step of narrowing down your choices.
I would then decide whether you prefer an innerspring/polyfoam mattress (like the two Orthopedic mattresses) more than your preference between latex or memory foam and of course the lower budget range may make a difference here as well. I would ask yourself if the differences between them in terms of PPP and the probable useful life of each mattress is “worth” any difference in cost to you.
There are many different types of innersprings that can be used in a mattress and each of them will have a different feel and performance (also depending on the comfort materials above them) but an innerspring isn’t normally the weak link in a mattress regardless of the type (the comfort layers are the part of a mattress that will soften, compress, or break down first) so the biggest practical difference between different types of innersprings and other types of support components would be based on what you feel when you test the mattress that uses them (or sleep on them) and how suitable it is in terms of PPP. There is more about the different types of innersprings in this article and in post #10 here. One of the biggest differences between a pocket coil and an innerspring that uses helicals is the amount of motion isolation so if you sleep with a partner then it would be important to test the mattress together to see the differences between different types of innersprings. If you don’t then this may not be as important to you.
Phoenix