Modern Coin Mart via eBay offers this 10 troy oz. .999 Silver Bar from the S.S. Gairsoppa Shipwreck for $272.67 with free shipping. That's $75 off and the lowest total price we could find, although we saw it for $33 less in December. It's one of almost 7 million silver ingots that sank when the S.S. Gairsoppa was torpedoed by a German U-Boat in the Atlantic Ocean on February 17, 1941. It's certified to be 99.9% pure and sealed in protective soft plastic.
Note: Silver is currently trading at around $21.57 per troy ounce.