having a high price
"costly jewelry"
"high-priced merchandise"
"much too dear for my pocketbook"
"a pricey restaurant"
Of high cost; expensive.
"The renovation project proved to be costly, running far over the original budget."
Costly comes from Middle English and originally meant simply "having a high price." The word entered the language by combining the root for expense with an adjectival suffix to describe something expensive.