Tax is not simply calculated at 32.5%*total income. If your annual income is $80,000, you will get $60,853 after tax, provided that your employer will pay separately for superannuation. If superannuation is included in your offer of $80,000, your net income will be $56,307. As Maggie mentioned above, public school is free to 457 visa holders in Victoria. But there will always be some costs on education like uniforms, textbooks etc. Health insurance costs $150+ a month. If your wife can get a job, maybe part-time since you have 3 children to take care, it may not be that tough.