Inkle loom - Used for making small projects such as belts. The loom is small and it is designed to create pieces up to 4.5 inches wide.
Table loom - More complex than the Rigid or Inkle looms, but just as small and portable. They are best when using lightweight fabrics.
Tapestry loom - This is a large, non-portable loom. It is able to create large intricate patterns and shapes with many differing yarns. With this loom you can create your own personally detailed pictures and images.
Floor loom - The largest, most efficient loom. This is used by professional weavers and weaving companies alike. It is very efficient, and can create very wide, large fabrics and rugs. This loom is the only one which allows the weavers to use their hands Polyester satin ribbon and feet to make the process go faster and more precise.
Just as the fabric itself can be pricey, so too can looms. Weaving can be a very expensive hobby depending on your materials and the project. If you are just starting however, it doesn't have to be. You can get started with cardboard and cheap yarns for practice, then move on to bigger more expensive projects as you improve. What's most important is the enjoyment you get from your hobby, not the price.