the game is not worth the candle

Từ điển Oxford Advanced Learner 8th

(the game is) not worth the ˈcandle idiom
(old-fashioned, saying)the advantages to be gained from doing sth are not great enough, considering the effort or cost involved
•If the price goes up again, he may decide that the game's not worth the candle.
Main entry: ↑worth_idiom