It is very common to talk about or discuss income, money issues with your colleagues or friends in China.
If someone is rich, people always except to get a treat from them. You can say '他有钱' -- tā yǒu qián
他 (tā) means he or him
有 (yǒu) means have or has
钱 (qián) means money

If you want to say 'He is very rich', you can say 他很有钱 - tā hěn yǒu qián

富翁(fù wēng) is a word to say 'rich man'