Great Britain
George IV gold Sovereign 1823 AU58 NGC, Royal mint, KM682, S-3800. Without a doubt the key date in this series, with a mintage of 617,000 (remarkably low for a supposedly mass-produced circulation issue). A couple of digs on the neck of George, and scattered hairlines, but they appear more inconsequential than they sound, as the eye is distracted by the lovely reddish toning throughout. As this date, in any condition, appears at auction only two or three times a year, any opportunity to acquire an example should be taken seriously.
Estimate: 6000-8000 USD