One 10 lb lot of 3 inch ingots from Quadruplate. Britannia metal is tin with antimony and a small amount of copper which some casters find toughens boolets. Where the silver plating goes-into the dross or absorbed in the melt is an unanswered question. $108 anywhere USPS Priority Flat Rate boxes go.
One 5 lb lot of the same, $58 shipped USPS Priority.