Has anyone ever used inflation in a game world?
Every time the party brings treasure out into the world there could be a knock-on effect, prices rising in the local area as the new money gets spread about, or those rolling in it get milked.
Or when an army brings its guns and requisition orders and there are shortages of the basics.
What new industries might spring up, and if there was a limited population, what might not get done? Where would the equilibrium be? Would everyone make for the caves and ruins in a new gold rush, or follow forces over the horizon for barter, auxiliary work or prestige? Would new centres of power and cliques appear, or a cargo cult form?
How about a realm leaving the precious-metal standard? After all, if one of the functions of money is to store value, it ought to be a thing that loses little value over time, and the aim of the game could be undermining that. It needs to be a good medium of exchange and unit of account too, but in a fantasy world there might be many things to do it better.
Even in our world there might be many things to do it better. How would our our own made-up money work in a fantasy world? Would it be laughed off, or be a scheme for a smart group to try? Could a pyramid get going, and would the lords and their lieutenants clamp down? Would the newly rich be allowed to take treasure into other realms?
And why would treasure bring experience anyway? I guess it's just a short-hand for the process of development in getting it. Maybe a better basis for that would be number of decisions or dice rolls made, maybe with a bonus for failure or injury, for the reflection.
Lots of questions. I didn't mention currency unions though. That could well be too raw._