Worth its weight in gold means so useful that no price would be too high. That tool is worth its weight in gold.
It is said of small practical things far more than of expensive ones, which is the charm of it. A person can be worth its weight in gold too, and the phrase does not change.
1phraseworth its weight in goldSo useful that no price would be too high.
“A good pair of boots is worth its weight in gold on that ground.”
worth its weight in gold is a phrase.
Practised in Idioms