moneymaker; money-grubber
Refers to a person who is focused on accumulating wealth, often with a slightly negative or critical tone. Not a neutral term for someone who simply earns money.
He has been a money-grubber since he was young, and now he has built up considerable assets.
That moneymaker doesn't waste even a single yen.
金持ち simply means 'rich person' and does not imply the active pursuit of wealth that 蓄財家 does.
Compound of 蓄財 (ちくざい, 'accumulation of wealth') and 家 (か, suffix meaning 'person who does that as a profession or characteristic').