The superlative form of an adjective has tow degrees: superlative of superiority (e.g. “the most expensive”) and superlative of inferiority (e.g. “the least expensive”). Both in Persian and English, there is no morphological way to construct the superlative of inferiority. In Persian, it is often expressed with the superior degree of an opposite adjective (e.g. “cheapest”).

ارزان is not the only antonym of گران. There are other antonyms that can be used in the above example.

In fact, a common pattern to express the superlative of inferiority is to use an adjective that derives from the prefix کم (“kam”: little). For example, کم‌هزینه means “having little cost” and کم‌هزینه‌ترین means “having the least cost”.

In the following example, the adjective کم‌آسیب means “causing little damage” and its superlative of superiority کم‌آسیب‌ترین literally means “causing the least damage”.

In the following example, the adjective کم‌خطر means “having little danger” and its superlative of superiority کم‌خطر‌ترین literally means “having the least danger”.