What is the Real Value

It is a live project given by British Art Medal Society about to submit a medal in annual medal competition and it has been exhibited in The British Museum.  

For the medal, I was inspired by a photo took in Hong Kong which was taken in market selling fresh chicken with price hanging.  However, one of the prices under is a head. I think the photo is not only showing a black humour, but also it is a really something worth to ponder about the relationship between human and value.