I've been in the US almost 9 months and now I hold a line with regular schedules (everyone starts off on 'reserve' after check to line). You can earn a decent living here when you get to this stage with overtime. The company I work for paid for my jet type rating with no bond nor minimal terms of service. I was paid from day 1 of ground school. And we're free to move on whenever we want and management infact understands this and won't hold you back. This video gives you an idea of what to expect.
https://www.youtube.com/watch?v=Nw76VbNJDjQ
I concur with Havick in that Mesa is probably the bottom of the barrel. When I started, there were only two US regionals that employed Australians on the E3 visa. Now there are quite a few to choose from. Ask around for which ones to choose, and which ones to avoid. Those with huge sign-on bonuses (and I mean huge) are probably those that the locals themselves are avoiding, so that will give you some indication.