Avaricious is a hard, judging word for a person whose wish for money and things is too strong. It is not only 'they like being rich.' It is 'they keep wanting more, and other people see that wanting as ugly.' You will meet it more in books, news, and quite formal talk than in everyday chat, where people usually say greedy. Though actually the two are not the same size: greedy can be about food, time, or attention; avaricious almost always points at money, land, or treasure. If you call someone avaricious, you are not describing them kindly. You are saying their love of getting has gone too far, and you do not respect it.