Dan Murphys have 5L kegs of Franziskaner Hefe (my personal favourite example of this style) for only $30, that comes out to be $3 per 500ml bottle!
It needs to be drunk within a couple days if you dont have one of those speacial dispensers that keeps the air out of it. Still I highly recommend everyone on this forum get a few friends together this weekend to demolish one of these!