Hi mduda,
Thanks for providing the specs of the foam layers in your mattress.
In terms of durability a mattress is only as good as it’s weakest link regardless of the quality or durability of any other materials and components in the mattress.
While most of the materials in your mattress are good quality and durable materials and components … I would be uncomfortable with having 3" of polyfoam in the top quilting layer which is lower quality/density than the minimums that I would normally suggest in the guidelines here for a one sided mattress.
Even though it’s better quality/density and more durable than the materials you would normally find in the major brands such as Sealy, Simmons, and Serta … they could still be a weak link that would affect the durability and useful life of the mattress and in your budget range I would tend to look for a mattress that used higher quality/density foam layers (or that had less lower quality/density materials in the top layers of the mattress).
Phoenix