This one is fairly obvious but when completing a side quest or assisting a citizen in some way there is usually an option that asks for payment or hints towards. An example of this is helping Grysca the shopkeeper in the Pearl District of Paradis it gives you an option that says (rub thumb and finger together) I didn't do it for free. Select these options 5 times and the cheevo will pop on the 5th.
So far no one has been angry that I have asked for money but if you are trying to be as good as possible in your save for whatever reason then it may be worth saving before you hand in a quest to get this achievement.
I didn't try saving and asking the same person 5 times so if someone wants to test that out I will happily edit this solution.