Yea it's sad how often this is the case. An old friend of mine actually ended up going out of business like this. Someone sold him 6,000 circulated morgan and peace dollars. Problem is he knew nothing about coins and only did silver tests on a handful of coins from the top of one of several large sacks. Turned out about 500 of the coins near the top of the sacks were genuine, the rest were base metal alibabas