chaffer vs drive a hard bargain

chaffer

verb
  • To haggle or barter. 

  • To talk much and idly; to chatter. 

  • To buy. 

noun
  • The upper sieve of a cleaning shoe in a combine harvester, where chaff is removed 

  • bargaining; merchandise 

drive a hard bargain

verb
  • To negotiate forcefully. 

How often have the words chaffer and drive a hard bargain occurred in a corpus of books? (source: Google Ngram Viewer )