Get more money
First be a viceroy. Then corrupt then the cities that are under your control. Leave no gold. Then resign or revolt. You can request the ruler (ex. Cao Cao) to widen your control (ex. 2 cities to five etc.). You will resign eventually so get all the gold to buy items in bazaars.
More tricks, tips and cheats for this game are right here - Romance of the Three Kingdoms X cheats
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