Stage 1. WoD and Legion Garrisons / Halls create stupendous gold inflation that will never be drained from the economy.
Stage 2. M+ provides an infinite, repeatable source of gear hence unbundling boosting from weekly lockouts.
Stage 3. Blizzard adjusts prices on repairs and "luxuries" such as reputation mounts and pets to be exorbitant to drain the excess gold from the economy.
Stage 4. The elites don't give a fuck about price adjustments. They just step up their infinitely repeatable boosting game and drain the gold from the proletariat to pay for 5 mil brutosaurs and 300k frogs.
Stage 5. In effect, the Garrison / Hall bourgeois become poor again because all of their gold has been drained by elite boosters to pay for gear, exclusive mounts, achievements and whatnot. The elite remain as rich as ever.
There's no "middle class" in this game anymore. Either you are an elite booster in the Gallywix community with an endless supply of gold and can afford everything in the game without batting an eyelash, or you are one of the destitute poor struggling to pay for consumables. Since Blizzard obliterated traditional ways of goldmaking such as professions, the entire economy looks like this:
The poor or the "whales" buy gold with tokens to pay for gear and exclusive content -> the elite boosters extract the gold from the poor -> the elite buy tokens with gold. In essence, the elite are exploiting the proletariat for free game time.