I saw this post over on Tenkar's Tavern today:
Do You Hand-Wave Adventuring Economic Effects?
Short answer: no, but without inflation.
I'm sympathetic to the idea that a lot of money hitting the market at once causes inflation. So does limited supply of goods. If both happen, zowie, your per-unit spending value drops. You may have 1000 gold instead of 10 gold, but 100 gold buys less than 100x what you used to be able to get for 10.
But it's a pain to put into play, without a computer, and no one likes it, even with a computer.
So I largely do the following:
- a big dump of like goods means each is worth less. PCs have tried to trickle-sell items to make up for this. They are able to do so, although my XP awards system discourages this, and I won't allow for Excel spreadsheeted sales trickles to allow for extra income over time. They can hold back and sell later and hope for a higher price, but again, my XP award system discourages this.
- I do random, big fluctations in prices and availability. Boom, magic items cost more. Bang, potions cost more (my players from my old GURPS game remember the magical disaster to caused a potion price rise.) Snap, the prices for certain services go up.
- I also kept track for a while of loot that hit town, and let spent money in town - not just held on to, but spent - increase the local economy. Over time, more good became available for purchase. The PCs basically "unlocked" access to better goods and services - the more expensive ones - by spending money in town.
I can report these all worked fine.