Memory Foam Mattress Topper question?

I wondered how much of the difference in the comfort of sleep between a mattress foam topper memory, which is 1.5 "compared to that of 4. I found a 1.5" Twin Memory Foam Mattress Topper at Walmart for $ 50 and also found a 4 "Twin XL Memory Foam Mattress Topper at Walmart for $ 75. Therefore, I wonder if it worth shelling out another $ 25 for additional 2.5 "of memory foam or simply But it is preferable that you try to lie about it to see how it feels. Some people prefer to sleep on a thicker topper.

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