worth its weight in gold
Because gold is expensive even in small amounts.
- (idiomatic) Very valuable.
I find my dog is worth its weight in gold on those long snowy weekends when I can't get out.
- 2011, "Summer (Where Do We Begin?)" (song), Phineas and Ferb the Movie: Across the 2nd Dimension
- Summer, every single moment is worth its weight in gold
- Summer, it's like the world's best story and it's waiting to be told
- When applied to a person, the pronoun its is substituted for a personal pronoun, such as his or her.