Differences in material quality and mattress performance, as well as manufacturing techniques typically contribute to the variation in prices of memory foam mattresses.
In reality, the huge differences in quality and performance between memory foam mattresses at the lower and upper end of the market all but makes them completely different products that can’t credibly be compared against each other.
Many cheaper mattresses sold as memory foam don’t contain any memory foam material whatsoever. See our Buyers Guide for more information on how memory foam mattresses can differ enormously.