f, as a backpacker, you are forced to pay hotel prices due to 5am flight from Berlin Schoenefeld you could do worse than Holiday Inn. 24 hour shuttle bus to/from airport, decent bar for food/drinks.....slightly expensive however if you are a budget traveller. Book online up to 14 days in advance to obtain best prices.
Address:
HANS GRADE ALLEE 5, BERLIN, 12529 Berlin Berlin Germany