Hostels are they way to save $$ in expensive Australia. YHA has coordinated east coast tours in conjunction with greyhound buses. Many of their locations have private rooms with two separate beds & bath which is way better than climbing in the top bunk in a dorm where your sleep might be impacted by a snorer. I'm looking for someone to share hostel private rooms in winter of 2019 (Jan-Mar). Booking ahead is key to securing private rooms. Airbnb may be an alternative if we get a group larger than two.
I'm in the SF Bay Area & my itinerary is open, but I think YHA has a good template. You can't travel Australia any cheaper than hostels & buses. I've been to 68 countries, but never made it to Australia. Most of my travels have been solo, but would like to travel buddie style more often. New Zealand has YHA hostels too; I would probably be interested in the South Island only.