Heard an ebay tale yesterday about a guy who bought an ultra modern satellite navigation system, which could be used in a car, bike, boat, walking, you name it. Bargain price of just over £200.
When it arrived it was a map and a compass, no kidding. Would have to say the goods description was pretty accurate.
I've got a mate who buys and sells coins and banknotes and he's never had any problem, though the sellers he deals with all have a ratings profile re the experiences of other buyers re condition of items, speed of delivery etc.
Buying without some sort of reference like this is asking for trouble.