I stayed at the Ethio-German Lodge, Debre Libanos last weekend for a Yoga course (organised by Yoga teacher from Addis). I loved the place, the views over the valley are amazing,
the staff were very friendly, but it was very very cold, so I would advise people to bring a sleeping bag (though my friend who stayed in the rooms in the back said they were warmer than the rooms with the view).
We didn’t eat their food (as we had our own ‘yogic’ menu) and I didn’t pay for the room directly, because we had a package deal,
but the room prices I was quoted by an employee were 250 birr for the front double room, 400 for the twin room, which I think sleeps 4, and the back room was 200.)
Tea and coffee were 5 birr each. I don’t know the other prices.
There is a nice short walk to the Portuguese bridge where they charge you 22 birr to cross, if you are staying for more than one day make sure you tell them, so they won’t charge you the next day again.