Not Worth A Dime Meaning

Example :   This vase is not worth a dime. Why did you pay so much for it?  His opinions aren't worth a dime.1878[1], New York Times:  Eight of the nine who got damages were not worth a dime, and all but six of those who failed to sustain their suits were worthless.2011, Baldev Seekri, Organizational Turnarounds with a Human Touch, page 211:  It is extremely vital, because without demonstrating performance and excellence, all the philosophies and reasoning discussed and embedded in the previous two phases are not worth a dime and will look hollow.