Consider this report found on SilverCoins.Com:
Tampered Gold Bar
I received a tampered gold bar from them. A 1oz Gold Perth Mint. I contacted them with no response. Several months later after I write a negative review on their website then they decide to contact me only to give me excuses of why they cannot provide an exchange.
If a firm offers you gold and silver at prices substantially below what its competitors are charging, you might want to investigate how it is able to produce such magic. Buying cheap but adulterated bullion isn't really a bargain, is it?