Well IMHO, this is a symptom of a really bad game design as gold is supposed to be scarce, you should find some other way to show off your server than insane amounts of gold! cause likewise it loses its value.
To answer your question, the solution would be to either change the gold data type, whether from within the source code or hack the executables, to hold higher values, or to transform the difference into some item with equal value such as million/billion dollar notes.