pricey vs costly

pricey and costly both are adjectives.

Word	Noun	Adjective	Verb	Adverb
pricey	No	Yes	No	No
costly	No	Yes	No	No

As adjectives, pricey and costly are synonyms defined as:

Other synonyms of pricey include dear, high-priced, pricy.

pricey (adjective)	costly (adjective)
having a high price	having a high price
	entailing great loss or sacrifice