As players spend more time on a game, ammassing wealth, prices inevitably soar.
In contrast to the real-world where the supply of money is usually, except rare exceptions, tightly controlled by central banks and regulatory authorities. Every mechanic in a game that rewards currency is spawning it out of thin air. Consider the ways a player can earn currency in a MMO (excluding player-to-player transactions since that money is already in circulation), loot drops, quests, event rewards, dungeon or raid completions, and etc. Inflation in MMOs is not a new phenomenon and is something that has plagued player-driven economies for decades since, unlike real-world economies, the amount of currency is never strictly limited. Barring developer interventions, the price of goods trends inevitably upwards.
MMO players are more familiar with the opposite issue of rampant inflation, as most MMOs do not have enough currency sinks to prevent the accumulation of money, leading prices for materials, armor, items, housing, or anything in-between to rise, often rapidly. More money is leaving circulation than can be replaced. Players in New World are experiencing a rare economic crisis, at least within the scope of online gaming: deflation.