Hi lovesleep,
I may be able to help you with how to choose but what to choose depends on all the parts of your personal value equation that are most important to you because each person can define value in very different ways.
Both of your choices use the same type of latex so from a quality perspective they are very similar and neither mattress has any obvious weak links in terms of durability. The Nutrition has an additional 2" of latex compared to the Total latex mattress so from this perspective the Nutrition has a slightly higher cost of materials but the Total latex also has a cover that is quilted with wool so it has more “value” in this part of the design. Given the significant price difference it’s certainly clear which of the two has the better “material value” since any difference in the cost of the materials in the Nutrition certainly doesn’t account for the difference in price although MAP pricing is usually not the best price available for the PLB mattresses … it’s just the best price that can be advertised (and as you mentioned your choice may also depend on the final price for the Nutrition although their offer to match prices may be based on finding the same mattress for less).
The material or commodity value of each mattress though is only part of the value of a mattress purchase and there are many other parts to value and other tradeoffs that may be important when you are making final choices. This includes your confidence about the suitability of either mattress in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences), how well you believe your testing will predict your long term experience, the level of risk with each choice that you believe you are taking, your recourse if you make a choice that is less than ideal, and any of the other objective, subjective, and intangible parts of a mattress purchase that are important to you besides the price or material value alone.
I think in most people’s terms it would be easy to say that the “value” of the Total Latex Mattress is much better and it has better exchange options as well but the importance of personal testing and your confidence that it will predict your long term experience is also an important part of any purchase and part of the “value” of a local choice. It really depends on whether the substantial price difference (assuming that’s what it ends up being) is worth any additional risk of an online choice, what the final difference in price (with a mattress only comparison) turns out to be, and which side of the price/risk tradeoff you feel best about.
Phoenix