The antonyms of the word "uncostly" are expensive, costly, high-priced, pricey, and dear. These words imply that something is not affordable or is beyond one's budget. Expensive items are usually associated with quality and luxury, while dear or high-priced items may be rare or exclusive. Costly goods can be attributed to their high production or maintenance costs. Regardless of the reason, antonyms of the word "uncostly" suggest something that is not easily affordable, and therefore, may not be accessible to everyone. Understanding these antonyms is important to communicate effectively, particularly in fields like marketing, sales, and finance.