Mezuzah, in Hebrew, means "doorpost". However, in today’s Modern Hebrew, as well as in other languages, it is more widely used to refer to the covered scroll parchment that Jews fix on their doorposts, as the Torah explicitly commands to do. This parchment contains a number of Biblical verses that laud God and His oneness and remind us of the miracles He performed for us, like the splitting of the sea and other events pertinent to the most famous Exodus in history. The Mezuzah scroll must be written by a professional scribe and is placed in a Mezuzah case, of which there are many, many types.
Certian religious items such as Prayer Shawls are worn in different enviornments depending on the sect of Judaism. For example, more religious Jews will wear the Tallit in the synagogue during services. Unlike Tallitot and other religious items that are used only by fully observant Jews, the Mezuzah is often used across the different movements and streams of Judaism, from reform to ultra-orthodoxy. Mezuzahs can be found in abundance in Judaica and online stores, and the only things you have to do are determining your budget and making sure the parchment is kosher. Once the former has been determined, you can start shopping around and being overwhelmed by a sea of possibilities.
Because Mezuzahs have to be affixed on all the doorposts in your home, you can buy Mezuzahs of several types to fit the "nature" of each room. At the main entrance to your house you may want, for instance, a beautiful sterling silver or ceramic Mezuzah; such Mezuzahs always make a good impression when first entering a house. For couples with children, there are modern Mezuzahs that confer a feeling of playfulness even before entering the room itself. These Mezuzahs are usually not expensive since they are made of comparatively cheap materials, such as plastic or even Fimo, which is a brand of polymer clay.
Among the popular types of Mezuzahs are the stunning glass Mezuzahs. These are often homemade and can be clear or colorful, silver or gold-studded, expensive or inexpensive; the list is long.
One of the things you need to keep in mind is the fact that the Mezuzah scroll will often count for the majority of the cost. Depending on the type and size of the parchment, prices range from twenty to over a hundred dollars. Factors affecting the price include the size of the parchment and the type of the parchment. For example, the clearer the parchment is, the more clearly the written passages can be seen. Additionally, when choosing a Mezuzah scroll, take heed of the different customs, for instance, Ashkenazi versus Sephardic Mezuzah. As always, if you are unclear on any issues of customs and legitimacy (kosher), you should consult a certified authority.