Bugger.

Thought I had a chance at his one.
"Clifford Berryman Uncle Sam Political Cartoon Original Art (undated). Terrific political illustration by the legendary Clifford Berryman, image area 14" x 13" and in Very Good condition. Also included is another illustration featuring Kaiser William, by an unidentified artist. This piece has an image area of 13.5" x 18.5" and the art is in Fair condition; the paper is very brittle with many tears and some chips out including a large section in the tree."
 

The thing being that the other illustration was a signed Thomas Nast.  If I'd been the only person to notice that, I would have got a $1,500 value for about $150. But I wasn't, and some tattletale even peached to Heritage Auctions, raising the bar for everyone:

"Clifford Berryman Uncle Sam Political Cartoon Original Art (undated). Terrific political illustration by the legendary Clifford Berryman, image area 14" x 13" and in Very Good condition. Also included is another illustration featuring Kaiser William, by Thomas Nast. This piece has an image area of 13.5" x 18.5" and the art is in Fair condition; the paper is very brittle with many tears and some chips out including a large section in the tree."

They've still got it as a picture of Kaiser Wilhelm rather than Bismark - Wilhelm would have been impossible for Nast - but that's not enough to keep the price within my reach.

It's still probably cheaper than I'll ever see a Nast again, but it's no longer a gift.