Your most expensive firearms book?
I got to looking up some of my books after looking up my copy of Peter Laidler's An Armorer's Perspective and it was going for $400. (That search turned up a very disturbing story about Mr. Laidler from 2017, but I'll leave it be) anyways I have a copy of Donald Bady's Colt Automatic Pistols 1896-1955 and Amazon is selling it for $912! And mine is first edition. Blew my socks off. :thup:
So what's on your bookshelf that would command top dollar? Or Euro? Or whatever?