kill for

would/could kill for (something)

A hyperbolic expression of one's intense desire to have or do something. Man, I could kill for some of my mom's homemade spaghetti right about now. I'm so jealous—I'd kill for a chance to go to Brazil for a month!
See also: could, kill
Farlex Dictionary of Idioms.

kill for something

Sl. to be willing to go to extremes to get something that one really wants or needs. (An exaggeration.) I could kill for a cold beer.
See also: kill
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • kill for something
  • would/could kill for (something)
  • have an appetite for
  • have an appetite for (something)
  • indoor
  • greatest thing since sliced bread
  • greatest thing since sliced bread, the
  • sliced bread
  • the greatest thing since indoor plumbing
  • the greatest thing since sliced bread
References in classic literature
He will frighten every head of game within ten miles, and I--I have to kill for two, these days."
Jungle Book
If you will kill for me the Wicked Witch of the West, I will bestow upon you a great many brains, and such good brains that you will be the wisest man in all the Land of Oz."
The Wonderful Wizard of Oz
And Tiger-Face, also, made another man to be his right arm, and to give commands, and to kill for him.
The Strength of the Strong
For instance, the first kill for an American-flown P-51 came over Dieppe in 1942 when Hollis Hills scored against an FW-190 in an RAF Mustang.
Professional reading