This anvil has the classic Colonial shape. If it has one hardy hole and no pritchel, it would date before 1820 and thus be valued partially based on it's historic value. It's in rough shape for a user, but it might hold a special value to a history buff.
If it's Colonial, it should be wrought iron with a welded face. I recently found a really nice Hay Budden 128 lb anvil for $150. It was covered in several layers of paint. I cleaned it up and was real happy with my purchase. Anvils are tricky. It's best to do some homework and know if it's a good buy or not. Find the book "Anvils in America" and study up. It may be the library. Lin