I figured that maybe because demand for ANU has seemed to go up (indicated by higher entrance requirements) there may not be as many accommodation vacancies as anticipated. Also, I don't think quite as many people have been moving out as normal because of housing insecurity. I know of a few people who don't want to stay in college this year, but feel that finding accommodation is too hard. At Burgmann, I think they've been more prepared than usual to move undergraduates to the postgrad village for this reason, although I'm not really sure.
To be fair, even though accommodation in Canberra is rather dreadful, ANU is one of the few universities that will guarantee first year accommodation (albeit from a range of quality). Recently Melbourne Uni students have been discovered illegally living at some place because they couldn't get affordable accommodation at all. I don't know of any other universities which care as much about ensuring viable accommodation for students than ANU - and this is a very difficult task. But if ANU is serious about this commitment, it will build more residential halls.
If you live in a UniLodge 5 share apartment thing, I don't think the fees aren't totally unreasonable ($198 per week) studio apartments are a bit much though. But yeah, for a 3 share is just too much, really. Sorry, memka.
Anyway, something in Dickson for housing would be nice, it's a bit of a hike, but walkable (and if you had a bike it'd be quite good). I imagine it would be slightly cheaper than in the city too. Even if you lived near a bus stop out in Belconnen or something, you'd probably be quite fine (as long as it isn't too far away from the bus stop - you may need to ask). Bus services in Canberra are much more reliable than in Melbourne. Also, if you have a share house and one of you has a car then you can ride to uni with them (assuming your timetables are compatible). The only thing is this stuff would probably involve some travel costs. Good luck.