Hi danielo247,
I think more in terms of the “value” of a mattress purchase than just the “material value” of a mattress and this always depends on how well a mattress purchase matches all the objective, subjective, and intangible factors that are the most important parts of your personal value equation. No matter what you pay for a mattress or the kind of “deal” you received … if it doesn’t match your specific needs and preferences and you can’t sleep on it then it would have little value to you.
Having said that … if your mattress was newly manufactured and wasn’t a floor model or a used mattress then it seems like you paid significantly less than the usual selling price for the Serta Renewal Refined and it would also compare well with other similar mattresses that used similar materials in similar layer thicknesses so based on the “material value” of the mattress (which is only one part of it’s overall value) it appears to me you did well.
In terms of any “weak links” in your mattress … most of the top layers are either medium quality/density (4 lb gel memory foam) or high quality/density (the 5 lb memory foam and the latex) and there is only an inch of lower quality materials in the comfort layer (the 1`" of “support foam” which is low density polyfoam) in the upper layers of the mattress which wouldn’t play a significant role in terms of its durability.
I would also keep in mind that when you look back on a mattress purchase many years from now you will remember much more about how well you slept (or didn’t) than you will about how much you paid for it although the selling price is of course always an important part of the value of any mattress purchase.
So if your sleeping experience is as good as the price you paid or you have good exchange options available to you if it isn’t then it seems to me you did quite well.
Phoenix