An 1804 Adams-Carter silver dollar (only 15 are believed to exist) went for $2.3 million in Cincinnati on 30 April – half a million or so less than might have been expected last year. Listed by Coin Values magazine as the world’s seventh-most valuable coin, the silver dollars weren’t ever circulated but were originally created as gift sets to be presented to rulers in Asia in exchange for trade advantages..

Cincinnati.com has the full story including the seller’s motives for disposing of the coin.