buy into vs contend

buy into

verb
  • To believe; to accept a craze or fad as valid. 

  • To buy stocks or shares of (a business). 

contend

verb
  • To believe (something is reasonable) and argue (for it); to advocate. 

  • To be in opposition; to contest; to dispute; to vie; to quarrel; to fight. 

  • To be in debate; to engage in discussion; to dispute; to argue. 

  • To struggle or exert oneself to obtain or retain possession of, or to defend. 

  • contend with: To try to cope with a difficulty or problem. 

How often have the words buy into and contend occurred in a corpus of books? (source: Google Ngram Viewer )