IDIOMS

hard nut to crack

(idiomatic) An amount that is difficult to finance.

Example: Used other than as an idiom: see hard,‎ nut,‎ crack.
1893, Grant Allen, Michael's Crag, ch. 11:
  He saw the dilemma. . . . It was a hard nut to crack. He could see no way out of it.
1991 June 14, Leonard Silk, "Economic Scene; Predicting When Upturn Will Start," New York Times (retrieved 22 Sep. 2011):
  Germany's inflation proves a hard nut to crack.
1928 June 8, "Mike McTigue Gives Emanuel a Real Fight," Milwaukee Journal, p. 2 (retrieved 22 Sep. 2011):
  The coast lad found the veteran Mike McTigue a hard nut to crack and judging from the look on the Californian's face when the final bell sounded, he was mighty happy that the fight was over.
2011 Jan. 12, Simon Shuster, "Will the E.U. Let Belarus' Despot Off the Hook?," Time:
  "But Belarus is a hard nut to crack, and it has used these methods to slip out of these East-West pincers before," says Alexander Klaskovsky.
1885, G. A. Henty, In Freedom's Cause, ch. 7:
  The next day Archie, with Andrew Macpherson and Cluny Campbell, made their way through the woods until within sight of the castle. . . .
  "It would be a hard nut to crack, Sir Archie," his lieutenant said. "Unless by famine, the place could scarce be taken."
1929 March 15, "Five Mexican Armies March to Meet Rebels," Reading Eagle (USA), p. 1 (retrieved 22 Sep. 2011):
  Durango, however, may be a hard nut to crack, as it is strong strategically and is reported guarded by 4000 rebels.
2008 Oct. 17, Barbara Wall, "Housing crisis? Not for the superrich," New York Times (retrieved 22 Sep. 2011):
  Nice work if you can get it, but the luxury market is a hard nut to crack.