Hi, I am not a mechanic, but a panel beater, so pretty much del with the same mindset of managers.
In my trade too, wages are usually advertised between $50 - $60,000 but like back home, you can discuss and try to get what you can out of them. There are a lot of jobs advertised for the motor trade, more jobs than workers so you can usually arrange a better deal. Locally, the beaters jobs are advertised around $60,000 but i am on $73,000, so goes to show that they are willing to pay if the need is great.
I have come over on a 457 and looking to change employers in a different area. Its a simple enough process to do so, you just need to find an employer who is registered to sponsor you. If you however are not tied to any particular employer like that, then happy days, your in an excellent position.
I am here on my own and $73k suits me fine. I have workmates with family who struggle on the same wages, but like anything, everyone has their own cost of living and what one person thinks is a lot, others will disagree
Good Luck