expression
for money; by means of money; money-driven
Used adverbially to describe actions motivated solely by money, often with a negative connotation. Common in phrases like 金ずくで動く or 金ずくで結婚する.
彼は金ずくで動くような男じゃない。
He's not the kind of man who acts just for money.
金ずくでの結婚は長続きしないと言われる。
They say marriages based solely on money don't last.
金目当て is a noun meaning 'aiming for money' or 'money-oriented', while 金ずくで is an adverbial expression emphasizing the means or motivation by money.
金の力 means 'the power of money' and is neutral, whereas 金ずくで often carries a negative nuance of being solely money-driven.
From 金 (money) + ずく (attached to, relying on) + で (adverbial particle). The ずく element is a suffix meaning 'by means of' or 'relying on', seen in words like 力ずく (by force).