Interesting thread this one. Coins that I sell come from three sources really - eBay, fairs, and auctions. I make good money on those I buy from eBay, and my margins are always squeezed on the coins that I acquired from auctions and fairs. That may be down to my frankly weak haggling skills when I'm face to face, or down to the fact that if I have made the effort to drive to Bracknell I don't want to come home empty handed. None of these confounding variables apply when I'm bidding on eBay, so I do wonder if a coins true value is more likely to be found by looking at eBay prices (achieved, of course!), because if we're thinking about the purity of the transaction, nothing else is involved in an eBay purchase. Just the coin. CCGB (eBay edition). Wouldn't that be interesting?