This afternoon, Heritage Auction Galleries will auction in Dallas, for a current minimum bid of $30,000, a 1788 first edition of volume 1 of The Federalist Papers. The book is the property of Nathan Harlan, a National Guard captain from Granger, Indiana, who purchased it in 1990 (while he was in high school) for seven dollars. In recognition of Capt. Harlan's forthcoming deployment to Iraq, the auction house has waived its usual commission, so Harlan will make a significant profit on the sale: about $770 for each of the 39 Federalist essays in that volume. (Sources here and here.)
Update, 10 PM EDT: The final selling price was $80,000 - so make that $2,051 per essay.