The 'street' guides in Gondar are very adept at ingratiating themselves by offering some kind of assistance and asking nothing in return and then turning up another day. Because they were so nice to you, you might be tempted to ask them about something or they will always ask what you have seen or plan to see and then offer to help you. Be VERY aware of the details of anything you plan with these young fellows. It is not uncommon for someone who speaks very good English on your first meeting to suddenly barely be able to understand you if there is an issue with the cost of the plans you made. A classic example is to negotiate a mini-van to see something in the area ie. Gongora. You agree on a price to take you there and back but when you get there they try to tell you it will cost again the equivalent of what you agreed was the round trip price. NEVER, pay the total agreed in advance and never agree to the revised rate. If you still owe them money they have no choice but to take you back to Gonder to get at least the initial agreed upon total.
It is unfortunate that this goes on because in other cities we have been to we have not had this scam attempt. In Gonder, it is definitely 'buyer beware' - always check other options before agreeing to a deal.