For US dimes, quarters, halves that are 90% the standard seems to be to figure 0.715 ounces of silver per $1 face (they use this to account for wear on the coins). So at $30/oz, you are looking at about $21.45 per $1 face.
For Morgans and Peace dollars, the minted weight is somewhere around 0.7735 ounces of silver per silver dollar. I don't know what the standard is for wear but use that as a starting point for the silver content.
For Morgans and Peace dollars, the minted weight is somewhere around 0.7735 ounces of silver per silver dollar. I don't know what the standard is for wear but use that as a starting point for the silver content.



















