Pretty Penny Meaning

(idiomatic) A considerable amount of money; a high price or a high income.

Example: 1850, William Makepeace Thackeray, The History of Pendennis, ch. 75:
  We shall have our branch line—our shares are up, sir—and we buy your three fields along the Brawl, and put a pretty penny into your pocket, Mr. Pendennis.
1921, John Galsworthy, The Forsyte Saga, part 1, ch. 6:
  He expected she was spending a pretty penny on dress.
2007 April 30, Barbara Kiviat, "Stephen Schwarzman," Time:
  Schwarzman's firm makes a pretty penny in a number of finance fields.