Not everyone plans to be the BBEG

Wizard: I'm not keeping cash, I'm buying paper and ink and scrolls with it.
Being a wizard is super expensive.
- Adventurers don’t know that. My horc fighter sees a wizard tower and automatically wants to raid it for magic weapons.
  
  Instead of magic weapons in the vault you just find 300 years of tax paperwork
  Even the lich king doesn't want to throw down with the IRS

This is why I loved the old Stronghold Builders Guide. Give your players a base, something to care about AND something to adventure for. "Give up? And only have 7 bedrooms? I think not!"
- Here's hoping Palworld spawns a BG3 spoof with a live market and politics...
- I'm partial to the 2e Castle Guide. Aside from some minor parts that book is system agnostic which I'm a big fan of. It also talks a lot about the culture around castles and who is needed to run one
- Shit that's glorious

As your income increases you increase your defenses. Guards, armored caravans, a bank to store your gold, a connection to the local ruler so guards respond quickly, etc.
Besides, a wizard is probably spending most of their profits and books and other spell supplies. They gotta fund that Wizard's Tower of Compensation some how.
- Overcompensation, you mean. /picklerick.gif

In a world where gold can be fabricated with magic, I imagine it would work like IRL diamonds. Synthetic diamonds are relatively cheap to make and just as (or even more) beautiful, but the only ones that have 'value' are the ones extracted destructively and with awful human conditions.
So you could make the caveat that because his gold is not 'genuine', it doesn't have market value.
- He's not making gold, he's making useful things he sells for gold. Fabricate turns an equivalent value of raw material into a crafted object, so to make 50 lbs of gold bars you'd need 50lbs of gold, but to make a piece of furniture you'd just need part of a tree and 10 minutes.
  Just as a note, there's actually too much gold that exists in the Forgotten Realms. IRL humans have only mined 187,000 metric tons of gold, and 2/3 of that was mined since 1950. Without getting into the nitty gritty too much, let's just say there's not nearly enough gold for every monster to have even a small collection of coins, much less every adult dragon falling asleep on a golden pile while everyone else works just fine on a gold standard or something like it.
  Is it the dwarven kingdoms out mining humanity? Is gold simply more common or perhaps available in easier, more concentrated ores?
  Or are wizards adding more gold from thin air, and dragons provide a natural deflationary pressure by being obsessed with making great hoards of coins?
  
  So you're saying the wizards and dragons are coordinating their efforts in an attempt to keep scarcity artificially high?
  I KNEW IT
  
  Is it the dwarven kingdoms out mining humanity? Is gold simply more common or perhaps available in easier, more concentrated ores?
  Probably a bit of both I'd imagine.
  
  There's a limit to what people can afford to buy, though. "Hey I made this sweet artifact it's worth 1000gp" "Cool, I can give you uhhh...THREE chickens for it?"
- No, no, they sell synthetic diamonds at jewelry stores now. They just cost the same as the mined ones, because of course they do.
  
  Moissanite is better anyways.

My Artificer wants to help people.
That's why he's building out magic-tech that can cyborgify(steampunkify?) animals.
Just because towns don't want rats equipped with eldritch cannons, flamethrowers or healing pulses isn't his fault. Its a stepping stone to putting those things on people.
- Unfortunately, your Artificer has accidentally ended up with a sworn enemy: a blue were-hedgehog with a need for speed and a taste for sausage sandwiches topped with chili.
  
  I now need to find a way to shift out the Hermit Crab that turns into his Eldritch Cannon for a mysteriously blue Hedgehog with attitude.
- And if that doesn't work your party can set up a side business saving people from rats equipped with eldritch cannons that seem to be increasingly common