a penny
Matthew 18:28
But the same servant went out, and found one of his fellowservants, which owed him an hundred pence: and he laid hands on him, and took him by the throat, saying, Pay me that thou owest.
Matthew 20:2
And when he had agreed with the labourers for a penny a day, he sent them into his vineyard.
Revelation 6:6
And I heard a voice in the midst of the four beasts say, A measure of wheat for a penny, and three measures of barley for a penny; and see thou hurt not the oil and the wine.