Cheap accommodation in Berlin

I've found four possibilities.  Please note that I've lived in Berlin, but haven't stayed at a hotel or hostel there.  So I can advise you about location, but don't have first-hand knowledge of the accommodations.

Hotel Pension Funk (near Ku'damm)

CityStay Hostel (in Mitte)

Andescher Hof (in Mitte)

Circus Hostel Weinbergsweg (in Mitte)

A cheap accommodation in Berlin can be found in the shape of a short term apartment rent , assuming you are not traveling alone you can find real cheap ones here:

http://www.berlin-ap.com/ 

I found 2 places that look inviting and inexpensive.

1. Generator. Storkower Str.160,Berlin, Germany 10407

A hotel which sells itself as Hostel, mainly to young travelers as the equipment in the rooms is very basic, but nevertheless very clean and well located. A high-rise modern building set back from the road. In the Eastern part of Berlin with excellent connection to public transport. About $41/night.

2. Apart Hotel. SCHWALBENWEG 18,Berlin-Schoenefeld, Germany 0

Ideal for travelers who prefer an outside-city-centre location but don't want to miss the comfort of a first class hotel. A modern high rise building with a facade decorated with blue pattern. The hotel is located close to the Airport Schoenefeld and within easy walking distance to a S-Bahn station (tube) which takes you straight into the centre of Berlin. About $69/night.

If you're staying for a week there are apartments that charge a weekly rate. It might be cheaper still? just look around the net. Here's a list I saw, but i dunno if that's what you're looking for: Berlin Apartments