Any best offers on mattresses? Which brand provide you better mattresses for back pain?

First you need to figure out what causes your back pain. If it is not caused by the mattress, a new mattress will not fix anything. And when most mattresses cost a thousand bux or so, you sort of don't want to buy something that is not what you need.

You don't give any information on which to base a guess, but it is fairly certain that you need to improve your diet. Bones are made of calcium, pads between them are made of vitamin C, muscles are controlled by magnesium, vitamin D is in there, and 36 other nutrients are needed in balanced amounts. Doctors will not tell you any such thing because they have no training in nutrition. You have to study the books and learn it yourself.

www.amazon.com/Adelle-Davis/e/B001J3RULO
www.adelledavis.org/
cronometer.com/ (I haven't tried the software.)
charlesatlas.com/ An exercise plan that has been successful for over 80 years and requires no equipment

But since you asked, the best mattress is a water bed but an air mattress is almost as good. You can buy a Beautyrest queen air mattress at Walmart for 60 bux. You will need an electric blanket under it unless you have a heated floor. An air mattress does not last forever, so buy two to have a spare.