At certain times of the month this site offer additional cheap Budapest hotel bookings with promotional discounts. These can be located on the Budapest hotel special offers pages.
http://www.budapesthotels.com/
Special offers by Budapest hotels:
Budapest apartment
Situated in the heart of city 2 new centrally located private studios with computer & free 24h internet access. Easy access to tourist attractions, excellent public transport facilities.
StewHarod
Well, i was looking for all the possible accomodations, but I couldn't find better deal than this:
http://uk.video.yahoo.com/watch/3005310/8592066
15 Eur for a room, in the middle of the city is a very good deal compare to the others.