The Nike Padded GK ($40) pant is typical of the genre.  The pants are polyester with padding at the hip and knee, stirrups, and drawstring waist.  The material provides some additional warmth for colder games, but still breathes enough for mild temperatures.

Most pants in this class are very similar.  They are almost exclusively black, baggy and look like riding pants.  I almost expect to see a red coat and English saddle.  The elastic at the waist and the stirrups is of a lower quality than typically used in team gear.  The fabric is also of a lower quality that we expect from Nike.

The padding is minimal and provides a bit of protection.  It is thicker at the hip than at the knee to reduce restriction of movement.  Unfortunately, the material over the padding tears after a few serious scrapes.  This can be patched, but these are really just one season pants.