Although memory foam was invented in the 1960s by NASA there is little evidence of health benefits due to sleeping on a memory foam mattress. Those that sleep on such mattresses say that they enjoy it but scientific studies neither support nor deny any health benefits.
Enough to break your neck.
The prices of Queen size Memory Foam mattresses vary greatly. They can sometimes be found on sale for about $300, or their price can get up to about $1000.
The benefits of using a memory foam mattress topper are, body weight is equally distributed, heat sensitive memory foam, provides extra pressure and relief for a more comfortable sleep.
Memory foam mattresses have gained extreme popularity over the past few years. Some benefits of a memory foam mattress include more restful sleep and alleviation of back or joint pain.
Memory foam mattress toppers can reduce pressure on certain areas of the body, this can reduce tossing and turning while trying to gain a good nights sleep. They can also make a bed that is too firm softer and more comfortable. Memory foam toppers are more money friendly than buying a whole new mattress. They come in a selection of sizes, are generally easy to find and are very durable.
There is actually more than just one one mattress manufacturer that has a memory foam queen sized mattress. But the most noteworthy company is Tempurpedic, which was the first to release this kind of bedding in 1992.
The benefit of a memory foam mattress is that it molds itself to your back and spine. However, unlike a spring mattress, it offers less support.
Some of the benefits of sleeping on a mattress made with Tempur Pedic memory foam include a better support for the different regions of the body, as the material presents less resistance to lighter parts thus better accommodating your weight.
You can find more information on memory foam mattress at this site: http://www.memoryfoammattress.org/ and when you are ready to buy Overstock offers shipping for $2.95.
Visco elastic memory foam mattress toppers come in a variety of sizes, such as to fit a single bed. Similarly, they do toppers for double beds, king and queen sizes too.
The truthful answers is: "It's the thickness you are willing to pay for". One manufacturer I know of makes memory foam mattresses in three configurations: The top 2" of the mattress is memory foam, the top 4" is memory foam, and the whole mattress is memory foam. The price varies accordingly. Personal Note: If you can't afford a memory foam mattress, try a memory foam pillow. Awesome, especially if you're a "side sleeper".
Tempurpedic is the most popular brand of foam mattress pad. There are many off-brand memory foam mattresses that do not have the same health benefits.