Ferengis do not live in a post-scarcity world. Money can be used to purchase rare goods (those that can't be easily replicated) as well as personal services. Critically, the possession of a positive amount of money at death is essential in being reborn into a new (and hopefully better) life.
It buys exclusivity
QUARK: I have a contract for which I paid considerably. All gambling on DS Nine happens at Quark's or it doesn't happen.
SISKO: A few bribes to the Cardassians when they ran this place doesn't constitute a contract, not in the eyes of the Federation.
DS9: Exclusivity
It can buy "one off" items
NOG: It's my money, Jake. If you want to bid at the auction, use your own money.
JAKE: I'm human, I don't have any money.
DS9: In The Cards
It buys sex
SISKO: He immediately made sexual advances?
SARDA: He said it was part of the job.
DS9: Captive Pursuits
It's required to rent a suitable wife
QUARK: Thank the Nagus that you didn't. Remember what happened with Nog's mother? Yeah, don't want to think about her, do you. Let me
refresh your memory. You signed a standard five year marriage contract
with Prinadora's father because you wanted to have a child. A simple
everyday business deal. But then you fell in love with your wife and
wanted to extend the contract. And you were so in love that you never
bothered to read the extension before signing it. So in the end, her
father swindled you out of all your money. Prinadora left you for a
richer man and you got stuck with Nog. Hooray for romance.
DS9: Doctor Bashir, I Presume
You can buy your own ship
ROM: He's owed you that shuttle for ten years.
QUARK: Ever since I loaned him the latinum to start up his munitions consortium. He always said that if he became a success, he'd
buy me my own ship. Now it's here.
DS9: Little Green Men
You can even buy your own moon
GAILA: Weapons is a growth industry. In a month, all your debts will be paid. In six months, the Ferengi Commerce Authority will be
begging to reinstate you. In a year, you'll have your own moon.
QUARK: My own moon.
DS9: Business as Usual
If you die in debt, you won't be able to bribe the guard to get into the divine treasury and you'll end up in the Ferengi equivalent of Hell
ROM: You don't think we're in the other place?
NOG: The Vault of Eternal Destitution?
DS9: Little Green Men
Latinum functions as karma. The more you have of it at death, the better reincarnation you can afford
ROM: Maybe this is the Divine Treasury.
QUARK: Oh, don't be ridiculous. The Divine Treasury is made of pure latinum. Besides, where's the Blessed Exchequer? Where are the
Celestial Auctioneers? And why aren't we bidding for our new lives?
DS9: Little Green Men
