My favorite method is to provide disposable items that are significantly more powerful than permanent items. But there’s a fundamental issue of game balance. An expensive one-shot item has to be VERY potent to justify its cost (and make the player willing to use it). But would having a few of this item in one’s inventory allow the player to simply blow through boss encounters with ease?

And then there’s early game versus end-game pricing. Things like curing at temples tend to be overpriced at low levels when you really need it, but by the time it becomes a reasonable inconvenience you can often have your own party members cast the same spells for free.

Gambling – a lot of “equipment-focused” RPGs (Diablo-style, Borderlands, etc) – sounds like a great idea, except in my personal experience I lose interest very quickly. I think only once – at lower levels – have I ever gotten anything worth keeping. In ANY game. When it is so clearly useless, people won’t use it, and it won’t be a money-sink anymore.

Some single-player RPGs do allow the player to purchase (and even furnish) houses. This becomes a nice thing to blow money on when you’ve got more than you know what to do with, but I don’t recall them ever serving a critical function beyond being a place to stash my stuff. It’d be cool if people came to visit you or something, but then you’d probably be playing The Sims instead of an RPG. But seriously – it’d be nice if owning property actually unlocked interesting new quests and storylines. (Actually, as I recall, this was the case in Baldur’s Gate II, but I don’t recall seeing it anywhere else).

Outfitting NPCs – while this is frequently an ability with NPC companions, the only game where I’ve seen this be a useful mechanic (rather than an amusing side-effect) for general NPCs is Din’s Curse. In Din’s Curse, the towns frequently come under attack, and outfitting the townspeople with your castoffs make defensive events a lot easier when the townspeople are a bit less vulnerable. I guess there was a game (Morrowind?) where you could reverse-pickpocket NPCs and cause them to wear some useless equipment… right before you attacked them. But that’s more in the ‘amusing side effect’ category.

Of course, there are also recurring costs – like equipment maintenance (always a favorite among players – NOT!), rent, taxes, docking fees, etc… but these are not frequently welcome unless they provide an advantage — like hiring a mercenary. Even then, they might be only grudgingly accepted.

Training might cost gold – frequently used in older CRPGs like Might & Magic. I’m kinda surprised this isn’t used more in modern games than it is. This is something that can easily scale with players as they acquire more funds. Higher-level training for higher-level (and richer) characters has significantly higher costs, right?

How about buying quests (or access to optional areas) for gold? Or bribery (if events calling for bribery are recurring and interesting – not just penalizing)?

If a game is going to go through the trouble of having an economy, why not make an interesting one where there’s always something interesting for a player to spend his character’s money on?​