From Longman Dictionary of Contemporary Englishsomebody would give their right arm to do somethingsomebody would give their right arm to do somethingWILLINGused to say that someone would be willing to do anything to get or do something because they want it very much I’d give my right arm to be 21 again. → arm
Examples from the Corpus
somebody would give their right arm to do something• These parents would give their right arms to get their kids into a prestigious school. 