Inflation in a large MMORPG is a real thing.
It is so difficult to think of good gold sinks.

Another problem though is player style.
I knew lots of broke ass Everquest players. They always had to buy the latest armor/weapon.
And then there were people with more plat than you could shake a stick at.
Just not equal or balanced at all... and not something you should try to balance.

I had a character that i farmed with. Kept every single copper coin.
I had a character that was a sales mule. Had more plat than my primary had copper.