extravagance vs high life

extravagance and high life both are nouns.

Word	Noun	Adjective	Verb	Adverb
extravagance	Yes	No	No	No
high life	Yes	No	No	No

As nouns, extravagance and high life are synonyms defined as:

Other synonyms of extravagance include highlife, lavishness, prodigality.

extravagance (noun)	high life (noun)
the activity of excessive spending	the activity of excessive spending
the trait of spending extravagantly
the quality of exceeding the appropriate limits of decorum or probability or truth