Andrew MarshallSHARETennessean Michael Sparks strolled into the Music City Thrift Store in Nashville last year, a normal part of his weekly agenda. He picked up a candelabra, a set of salt and pepper shakers and an old copy of the U.S. Declaration of Independence. He paid $2.48 for the latter item, a "standard price" according to store manager Kay Boner.The "standard price" was altered significantly a year later when Sparks sold the document to a Utah investment firm for $477,650, causing a national stir.The copy happened to be one that John Quincy Adams commissioned William Stone to make...…Andrew MarshallSHARETennessean Michael Sparks strolled into the Music City Thrift Store in Nashville last year, a normal part of his weekly agenda. He picked up a candelabra, a set of salt and pepper shakers and an old copy of the U.S. Declaration of Independence. He paid $2.48 for the latter item, a "standard price" according to store manager Kay Boner.The "standard price" was altered significantly a year later when Sparks sold the document to a Utah investment firm for $477,650, causing a national stir.The copy happened to be one that John Quincy Adams commissioned William Stone to make...WW…