When it comes to describing an excessive or exaggerated amount, there are many words that can be used as a synonym for "outrageous amount." Some alternative phrases include "exorbitant quantity," "excessive number," "lavish sum," "extreme abundance," and "overwhelming mass." Additionally, words like "prodigious" and "towering" can be used to describe the sheer magnitude of a large quantity, while "appalling" or "staggering" can convey a sense of shock or disbelief at the amount involved. Ultimately, the best synonym for an outrageous amount will depend on the context and tone of the writing, as well as the specific impression that the writer wants to convey to the reader.