My son sent me these pictures from Cambodia. He is there on a short stint with a non-profit organization providing dental treatment to people who I presume are poor and in need. I am happy for him because I think the greatest gift one can give to another is that which the other person needs the most. Think of it this way: if you give $100 (in cash or service) to a rich man, that will not mean much to him. but if you give $100 to a penniless man, it means the world to him.
I cannot find anywhere in the bible that compares giving to the poor versus giving to the rich. However, this is almost like the story of the poor widow in the Gospel of Mark 12:41-44, except from the perspective of the receiver. (In that passage, Jesus observed a poor widow giving just a few copper coins to the temple treasury. Jesus said, “Truly I tell you, this poor widow has put more into the treasury than all the others. They all gave out of their wealth; but she, out of her poverty, put in everything—all she had to live on" ). In that sense, if one has no material possessions, he is going to be grateful for even a small little gift.