You might find this thread on a scam board to be helpful Ethiopian Student Scams. Read the post by A. Faranji and the one below it. The second poster notes that the scam is prevalent in Lalibela.
A Thorntree post about Lalibela scams Lalibela Scammers
A blogger The Lalibela Boys. All about boys who have been sent to Lalibela for school, study in the morning and work in the afternoon. She was scammed by them, but only for 100 birr.
Wikitravel:
More than any other city in Ethiopia, you will encounter many children who will approach you and ask for money. The greeting of "Hello money" is a common one. A typical scam is to ask you to purchase a dictionary for their school, which the overpriced tourist shops just happen to carry for $50 each - this is a scam. It may pain you to ignore these kids (especially those who grew up in the West and remember the 1990's famine post-Derg). Many will tell stories about coming from the countryside and having to pay their own schooling, or not having shoes. While they are undoubtedly poor, these are lies to try to guilt you into giving them money that they can spend on buying a material good instead of life necessity. Children will tend to congregate outside of the Mountain View and Tukul Village hotels as they know that these are the nicer ones with provide more targets of tourists with money.
If a child tries one of these schemes on you, do not hesitate to politely tell them that you cannot give them any money since it will just encourage them to tell lies instead of growing up to be an honorable person. Ethiopia is a socialized state where almost all of the basic necessities of life are provided. For sure the children who approach you are poor, but do have free education, housing, clothing, and meals; typically they are looking just to make some extra money to buy a football jersey or some other material good to show off to their friends. The adults on the other hand are very kind and friendly, and frown on this shameless behavior from their own kids but cannot stop it.
