an arm and a leg vs pricey

an arm and a leg

noun
  • Usually used after the verb cost, but also often charge, pay, and spend: a very high price for an item or service; an exorbitant price 

pricey

adj
  • Expensive, dear. 

How often have the words an arm and a leg and pricey occurred in a corpus of books? (source: Google Ngram Viewer )