You see, when you travel the full distance (from the beginning of a route to its end) you have to pay ETB 1.95. The problem arises when you pay ETB 2.00, and wait for change that is ETB 0.5 - you will wait in vain.
The most probable reason you will be given is that the tout has run out of change. And he tells you you will have to wait until the termination of the trip to get your change back.
If you need to get off in the middle of the of the route you will have to forfeit your 5 cents.
But even if you do travel to the end of the route and get off at the terminus, he will either pretend that he has forgotten about your 5 cents. Or go looking for moneychangers who will give him change for his ETB 1.00. He will make a real job out of it: first he will go running to find the furthest one, haggle, chat a bit, tout his route...anything to make you walk away.
But if you just stay put, and want to waste a good twenty minutes, he will eventually come back and grudgingly give you your 5 cents... wondering how stingy you are!
They count on your getting frustrated and walking away. Now the minibus transports 11 passengers, lets not even talk about the ones that are squeezed in, and per trip the tout is going to make at least ETB 0.55. If the taxi makes 20 trips that adds up to ETB 11. Now imagine how many taxis there are in the city and how much is being ripped off...
You will be well advised to carry a coin pouch and tender the exact change!