Hi goodmattress,
Post #21 here has a list of the members here that I use for making value comparisons. To get to “roughly equivalent” local value I would add about 20% - 25% to the range of prices there to offset the increased risk of an online purchase vs a local purchase. Of course each person may have a different risk tolerance and choose a different number to get to “equivalent value”.
Some of the other parts that will affect both the price of a mattress and its value to each person are the other options and benefits that come from dealing with a particular store or retailer both before, during, and after a purchase and which can’t be separated from the cost of the mattress itself. Some of the many things that may be included in the value of a mattress is listed in post #46 here and is part of what I call each person’s “personal value equation”
When you are considering latex and making comparisons then it’s also important to make apples to apples comparisons. This means making sure you are comparing the same type and blend of latex. Talalay comes in 100% natural and blended versions and Dunlop also comes in 100% natural and different blends as well.
I would also consider the type of cover that is being used because this can also be a significant part of the cost of a mattress.
Having said all that … if the Talalay they are using is blended Talalay then on a raw materials basis the single 6" layer would seem a little on the costly side yes. The extra 3" for $300 (if its the same Talalay) seems like a good price and the two together would also be much more reasonable in this case. The Dunlop … if it’s 100% natural also seems to be much better value and with an extra 3" for $300 would be good value (assuming that the Dunlop is 100% natural and depending on the cover).
Sleeping directly on 44 ILD Talalay also seems very firm to me and is the firmest Talalay latex they make. It is typically used in “super firm” support layers. You can see the Latex International ILD range here.
Your own personal testing would also be more accurate than any “theory at a distance” but a 6" base layer with no comfort layers may be a bit on the thin side for someone that was 300 lbs IMO. If you make up for this by making it so firm then you would be sacrificing pressure relief and the lighter part of the couple (in this case you) would likely experience pressure points and possibly both of you well. It certainly doesn’t seem to me to be in the “normal” range.
Phoenix