I've probably seen around five people concerned about their study score between the 50-75 range. Allow me to start off by mentioning that I am in that category, so this isn't just going to be some comforting post by some high achiever.
There are still plenty of opportunities at University for 50-75 ATAR students. You can still do well respected courses such as Business, I.T, Health Sciences, Education and Arts. These jobs can lead you into successful careers and further study. If you do well in your first year, you can transfer into another course (with ease internally afaik if you get good scores and there isn't a major demand).
I'm in contact with a few students doing I.T right now and are already making $40/hr part-time while studying fulltime. I have a friend who scored low 60s and he's working in computer security on great wages. I know some people programming casually and making good $$.
Same applies for non-IT subjects, you could be doing a few Accounting jobs here and there while making some $ and doing a job.
What I'm trying to get at is that you dont need a high ATAR to make money in life. I don't even think there is a strong correlation between ATAR/Financial success. I'd say it's somewhat moderate perhaps - I have no source so don't attack me here mr sauce(wo)men.