Synonyms for Extravagance (same or very similar meaning)
WordNet sense 1 (the quality of exceeding the appropriate limits of decorum or probability or truth):
extravagancyWordNet sense 2 (the trait of spending extravagantly):
prodigality, profligacyWordNet sense 3 (excessive spending):
lavishness, highlifeFrom the ODE community, based on WordNetadd/edit