earn your corn
earn (one's) corn
To be worthy of the money that one is being paid. I think you should hire the most experienced candidate because she'll definitely earn her corn.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
earn your cornBRITISH
If someone earns their corn, they are successful and therefore justify the money that has been spent, for example on employing or training them. New striker, Steve Menzies, earned his corn with a last-minute goal. Managers earn their corn in these difficult circumstances.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012
earn your cornput in a lot of effort for your wages. British informal
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