Following on from the Ainsbrook prog, i wondered if anyone has actually bought any coins etc from dealers/e-bay etc?

Never have, or would myself.
Google "Coincraft", or visit their shop.
It's right opposite the British Museum

following time teams lack of objectivity then isnt it a case of anyone can buy a metal detector and have trillions of pounds worth of disclosed bounty in minutes hence there would be no reason to buy anything