best wishes vs goodbye

best wishes

intj
  • Used as a polite way to end a letter or see someone off. 

goodbye

intj
  • Farewell; a formula used to another person or persons when the speaker, writer, or person addressed is departing. 

noun
  • An utterance of goodbye, the wishing of farewell to someone. 

verb
  • To say goodbye; to wish somebody farewell on parting. 

How often have the words best wishes and goodbye occurred in a corpus of books? (source: Google Ngram Viewer )