not worth a red cent
Worthless. I don't know how I'm going to tell that woman that her prized collectibles are not worth a red cent.
red cent, not worth/don't have a
Worthless; bankrupt or broke. The cent has long been the lowest denomination of American coin, and “red” refers to the fact that it used to be made of copper. The expression dates from the early nineteenth century. J. S. Jones used it in People’s Lawyer (ca. 1839): “It would not have cost you a red cent.”