I did a short trip to Luanda... 3 day. The prices caught me by surprise... a simple "McDonald's" style meal for two ran about 45USD at a new mall. Our daily Per Diem wasn't enough to cover the hotel cost. We had to dip into our own funds and get reimbursed later. I didn't see any middle class neighborhood in the few days that I was there. I think the best way to see Luanda is passing through on someone else dime with a roll of cash in your pocket.