They're all liars, basically. All of them "are saving up for some medicine", "need to buy a pair of shoes", are "old war veterans", etc. They put on these weak, pathetic voices so they can get our sympathy. Then if we want to talk to them more in detail about a particular topic, they reveal themselves. They're jsut ordinary Bretons, dark elves, etc who have found a great way to make some gold....
...So I give them EXTRA money by going into the Speechcraft menu and giving a bribe! Despite the 30 coins now in their pocket, the next time I see them, they're still "saving up for some medicine, needing to buy a pair of shoes", etc.
But it's just like many beggars in our world, who also constantly lie! In the modern world, beggars are looking for a handout so they can "make change to catch the bus" or "get something to eat" when really they're just looking for their next drink or fix. I've actually given money to beggars before who are more honest, and actually say they're alcoholics or whatever.