You are correct. I was thinking of the US Silver Eagle which was made 1 oz for the convenience of silver purchasers.

The US silver dollar has .7736 TO of silver content, not .900 TO, so my estimate of the melt value of the auction coins was high. Remember though, that there is usually a premium over melt value for US coins due to their easy recognizability and wide acceptance. Premium wouldn't make the value as high as I indicated though. The coins in the auction of course do have collector value, and no one will be melting them for their silver content till silver gets back to around $50 an ounce.