Everyone wants to purchase a mattress while it is on sale, and we dont blame you. But the average cost of an natural certified latex mattress in a queen size is generally around $2999 for a good quality high density latex. We have i-adjust on sale now for $1899 in a queen and $2399 in a king. These mattresses offer 3 layers of custom supportive dunlop latex in a zipper encasement. Buy online now and save.