The marimba is played by striking the bars with mallets which come in a wide variety of shapes, coverings, weights, and sizes. Some mallet heads are simply made of rubber or other synthetics graduated in hardness from soft to hard. Other mallet heads consist of a core covered with yarn, cord, or rubber. By controlling the core and winding a large variety of timbres are possible. Click here to view a variety of mallet heads.
Marimbas are, unfortunately, very expensive.
A good marimba will typically cost you as much as a decent piano. If you can find a used one, so much the better. Like most fine musical instruments, a marimba will not wear out. A used one is as good as a new one if it has been taken care of. First, the bars on the better instruments are usually made of rosewood which has gotten very expensive.