Posted By:
HankronRelevant notes on the two photos.
The 1882 cabinet has a stunning image in all ways-- superstars, fantastic pose, FANTASTIC uniforms, equipment. As the image was (I think) used to make a Harper's Woodcut, that will only enhance it's value and desirability. Though there is nothing special about the size/overall style, the image is as good as they come, and deserves a good sell price.
The 1882 Imperial Cabinet (8x11 or so cabinet-style cards are called 'Imperial Cabinets') is rare due to its large size. Imperials from before 1895 are rare and because of that and its display value usually receive a big premium in price. If the photo was even larger, it would receive and even larger and larger price (Maximum possible size is a bit over 20 by 20 inches). Realize that it was difficult and expensive to make large photographs in the 19th century, so especially large ones were reserved for special occasions or people who could afford them. Though I'm not in love with the 1881 image (as opposed to the 1882 cabinet), it would have been a steal at $1,500.