The antonyms for the word "free cost" are numerous, depending on the context of usage. Some of the most common antonyms for free cost include expensive, costly, dear, pricey, exorbitant, and steep. These words describe charges or fees levied against a particular product, service, or action. If something is not available for free, then it has a price, which can be unreasonable or affordable, depending on the individual's budget. Regardless of the antonym used for "free cost," it is crucial to understand that everything has a value that one must pay, whether it be tangible or intangible, emotional, or monetary.