Yes, it is. The adverb means to do something in a lavish or expensive manner.
"Extravagantly" is an adverb.
Extravagantly is an adverb.
Those who spend money extravagantly (adverb) and indulge in extravagance (noun) are called extravagant. (noun)
The adjectives paid or paying do not have adverb forms. The verb pay is an action that does not lend itself to a way of acting as do expensively and extravagantly.
Immoderate is the Latin equivalent of 'profusely'. It's an adverb that literally means 'without measure or rule'. The adverb 'profuse' isn't an equivalent. Instead, it means 'in disorder' or 'extravagantly, lavishly'.
He walked by me extravagantly with his black people hair.
At the Christmas party she was dressed very extravagantly compared to others that were there.
She dressed extravagantly, with a fur coat, diamond jewelry, and designer shoes, making heads turn wherever she went.
Splurge
Those who spend money extravagantly (adverb) and indulge in extravagance (noun) are called extravagant. (noun
spendthriftwastrelprodigal
profligate