Rather tantalizingly captioned "For Your Personal Collection" in the upper left corner, this double page spread from Our Fighting Forces #155 by Jack Kirby and inker D. Bruce Berry is an interesting combination of two things that Kirby is well-known for: "Kirby Machines" and World War II. Our Fighting Forces #155 was published by DC Comics in 1975, which also means this largely comes in between his Fourth World saga work at DC and his return to Marvel for titles such as The Eternals, 2001: A Space Odyssey, and Machine Man.
His hallmark 1970s era style is in full effect here. Everything he did at this time had a huge, cosmic scope, and you can see from his descriptions of the "Big Boomer" artillery he had drawn here that he thought of these weapons in a similar way: huge and stunningly destructive. Overwhelming force.
That aside, with the New Gods film just announced and more attention to this 1970s-era Kirby than ever, that is a ridiculously low price for a Jack Kirby double-page spread.