Thy price one penny is in time of plenty,
In famine doubled, 'tis from one to twenty.
Yea, no man knows what price on thee to set
When there is but one penny loaf to get.

Comparison.

This loaf's an emblem of the Word of God,
A thing of low esteem before the rod
Of famine smites the soul with fear of death,
But then it is our all, our life, our breath.

John Bunyan

http://www.poemhunter.com/poem/upon-a-penny-loaf/