Very fascinating and inspiring read!
I run a small browser-based MMORPG and I've seen a lot of interesting metagames play out in the game economy.
One thing I thought of while reading this is the effect of scarcity. I specifically remember one time when a stupid bug made the world a post-apocalyptic wasteland.
My game has a political aspect where one player is the ruling king, giving them a few unique abilities such as setting taxes. It’s a powerful position and players are constantly fighting for the throne. The way this works is that the king hires NPC guards to defend and protect the throne. The more guards, the more expensive and time-consuming it is to dethrone the king. The downside is that the upkeep to staff a full kingsguard is equally expensive. This has naturally made it so that only the wealthiest players can actually afford to sit on the throne and the easiest way to accumulate wealth is to run a shop.
The economy is centered around resources and mining. Normally the mines are replenished from time to time but the bug broke this mechanic. The first thing to deplete was the noble metals such as gold and silver, the same metals that the wealthiest merchants made their fortune from. With prices going through the roof a class division was created between players who had accumulated metals before the bug and players who hadn’t.
The problem is that without good gear you have no chance of coup d'etat. Even if you had a gold armor and sword you need a constant influx of new gold in order to repair them when fighting the guards. Even bronze became a rare commodity.
In effect, what happened is that the kingdom became a dictatorship. The king could set maximum taxes without any consequences. Normally such action would start a riot, have all players get their pitchforks and create a rebellion but without good weapons this was impossible.
I finally got around to fix the bug once normal iron started to run out as well and new players were restricted to useless wood gear, barely enough to kill rodents. I lost a lot of players but it was a really interesting social and economic experiment.