on the market vs purchasable

on the market

prep
  • single; not in a committed romantic relationship or otherwise unavailable. 

  • Offered for sale. 

  • During a real estate auction: going to be sold at that auction, i.e. the bid has reached the vendor's reserve. 

purchasable

adj
  • able to be purchased; available for purchase 

  • affordable 

How often have the words on the market and purchasable occurred in a corpus of books? (source: Google Ngram Viewer )