money rules the world; rich man's world
Proverbial expression meaning that money is the most powerful force in society; often used with a cynical or resigned tone.
Since money rules the world, you can't do anything without it.
彼はいつも「金の世の中だ」と言って、仕事に励んでいる。
He always says, 'It's a rich man's world,' and works hard.
A set phrase composed of 金 (money), の (possessive particle), and 世の中 (world, society). The exact origin is uncertain, but it reflects a common cynical view of society.