A thousand dollars may not be much for you but most Gold comes from countries where a $1000 goes a long way.
We had one recently where we signed contracts, told the shipment was in Dubai and they needed $7000 to release the goods from customs. 3) Asking for a letter of introduction to business.
A variation on this theme is the girlfriend or boyfriend befriending you and then promising to come visit / marry and just needs a few thousand dollars to release gold to sell to cover their trip. There are many variations on the scams listed and of course every one will claim that they are the real thing and have had problems with fake buyers before and dont want to get caught again.
(In some cases it may be true) The main lessons are not to put any money up front and not to send documentation out to someone you don't know.
These funds are not to be paid out until completion of the deal, giving the buyer security.