Hi seekeroftruth,
A mattress is only as good as its construction and the quality of the materials inside it so I wouldn’t consider any mattress where you weren’t able to find out the specifics about what was in it. This would be particularly true about the comfort layers (the upper layers of the mattress) which are the most prone to early softening and breakdown but I would also want to know the specifics of all the other layers as well. Serta doesn’t provide this information for most of their mattresses which is one of the reasons I suggest avoiding them completely but I would also avoid any mattress where you aren’t able to find out the specifics of what is inside it because otherwise you are making a completely blind purchase and won’t be able to make an informed decision or make meaningful comparisons with other mattresses.
If a salesperson doesn’t have the specific information you need available then part of their “job” would be to call the factory (or have someone call the factory) to find out the density of any polyfoam or memory foam in the mattress. “Quality” is a meaningless word without this information. Many of the Restonic factories will provide this information to their retailers so they are the ones that should be tracking it down for you.
Unlike polyfoam and memory foam … the density of latex is not a “quality spec” and you don’t really need it. It is more closely connected to the softness/firmness of the latex which you can feel with testing anyway. The relevant information for latex is the type (in this case Talalay) and the blend (which is probably a 30% / 70% blend of natural and synthetic latex). Latex is a good quality material though no matter what type it may be.
In other words what you need to assess a mattress is a list of all the layers and components from top to bottom which includes the thickness of each layer in inches, the type of material, and the “quality” of that material (density with memory foam and polyfoam and type and blend of any latex).
I agree this is a very high price for a latex hybrid if it only has 4" of latex over a polyfoam support core. As you mentioned … similar mattresses would be available for very much less.
You can read a little more about the different types of latex in post #6 here and in post #6 here (which are similar) but Talalay and Dunlop are just different … one is not “better” than another. You can also read more about covered layers vs bare layers in post #2 here and post #10 here.
I would treat the choice between Talalay and Dunlop as strictly a matter of preference and not in any way as a “better worse” comparison. In other words I wouldn’t get caught up in any of the “better worse” comparisons that are so common everywhere because most of them are misleading. You can also read a little more about the difference in “feel” between them in post #7 here but it’s usually better to test them in person because that’s the most reliable way to know which one you prefer.
Phoenix