The most expensive poster sold on eBay recently,
The Creature from the Black Lagoon six sheet.
It sold for somewhere between $35,000 and $41,000, according to the recent "completed listings" link, which also shows a few other very nice posters.
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&LH_Complete=1&_nkw=poster&_sop=3A few from Buffalo Bill Cody's Wild West shows.
One of these three sheets is at the Buffalo Bill Center of the West, in Cody, Wyoming.
Buffalo Bill's Wild West poster of Native American Chief Red Cloud.
The third most expensive sold on eBay recently, for $12,000,
In 2 Days to North America! I'm not a fan of pieces with Nazi symbolism, although I understand the historical aspect of items from that time, this poster has awesome art of the Hindenburg Zeppelin and the Manhattan skyline.
The photo is from the Smithsonian, from this link:
http://airandspace.si.edu/collections/artifact.cfm?object=nasm_A19900975000Also from the link:
Throughout their history, posters have been a significant means of mass communication, often with striking visual effect. Wendy Wick Reaves, the Smithsonian Portrait Gallery Curator of Prints and Drawings, comments that "sometimes a pictorial poster is a decorative masterpiece-something I can't walk by without a jolt of aesthetic pleasure. Another might strike me as extremely clever advertising … But collectively, these 'pictures of persuasion,' as we might call them, offer a wealth of art, history, design, and popular culture for us to understand. The poster is a familiar part of our world, and we intuitively understand its role as propaganda, promotion, announcement, or advertisement."