Copper is not traded in troy weights, but in avoirdupois. A 40% half is 11.5 grams total. 60% copper is 6.9 grams of copper per coin. 2000 coins is 13800 grams of copper. Avoirdupois is 28.35 grams per ounce, 16 ounces per pound. Roughly 30 and 1/2 pounds copper or $95 at $3.11 spot. Splitting hairs, but the final dollar amount wasn't the point.