They're incredibly sleazy scumbags. They buy silver coins at bullion-value or below, which is the lowest grade you can get for a coin, making a small profit on everything they buy and massive profits on the ones that are actually worth something as coins rather than bullion. And it's typically elderly people they rip off, who are thrilled to get the price of a cup of coffee for their 1884S Morgan dollar. Never, ever deal with these predators.