Innerspring mattresses are the most traditional form of mattress. There is a large price variation on these types of mattresses. Price is determined based on the quality of construction, which includes the frame, coils, ticking and fabric. Box springs are also an important part of the mattress selection-Look for a box spring that is steel-reinforced. It is also important to purchase a new box spring with your mattress as it will add several years on to the life of your mattress. When looking for an innerspring mattress, there are several items to look for:
Number of coils: This will determine the quality of support.
Gauge of the coils: This will determine whether the support offered is firm or soft.
Interconnecting wire between springs: Look for the amount of wire there is. The more wire there is, the longer your mattress will hold its shape.
Pillow Top: A pillow top will add more cushion to your bed, which is great if you are looking for a firm, but soft feel. A common mis-conception is that a pillow top provides better support-support comes from the coils, not the top, so whether you go for a pillow top or not will be based upon personal preference and budget.
Memory Foam: Mattresses made with memory foam contours to your body, forming a nightly personalized cushion. While most find these mattresses to be very comfortable, some people feel that memory foam mattresses are not as breathable as other types of mattresses.
Latex Foam: Mattresses made with latex foam can be more expensive than other materials, however, it breathes well to keep you warm in the winter and cool in the summer, is anti-microbial, hypoallergenic, and conforms to your body in a springier fashion than memory foam.

Be careful when making the purchase:
Because of the potential for spreading illness, mold, bacteria, and even bed bugs, it is illegal to sell a used mattress in the United States. Be sure to find out the history of your bed before taking it home-purchasing a floor model or a bed than an unhappy customer has returned can be just as harmful as purchasing a used bed.