high-priced vs costly

high-priced and costly both are adjectives.

Word	Noun	Adjective	Verb	Adverb
high-priced	No	Yes	No	No
costly	No	Yes	No	No

As adjectives, high-priced and costly are synonyms defined as:

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

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