Task: Question Answering
Input (English): Context: I pledged myself , and headed home , where I was met by another in service to the Word , but in a much different way . He granted me my staff , an instrument of the Word which would grant great magic ... but cost me a good leg . I also would end up , in my dreams , visiting a world ravaged by the Void . 
Question: What does this person mean when they say the staff cost them a good leg ?
Output (English): This is a figure of speech , what they mean is that it is was a costly purchase.