Which is suitable for life depends on what kind of life you like. Sydney is relatively more prosperous and has more nightlife. Brisbane is more natural and the air is good. Some people may find it a bit boring. Brisbane is sunny all year round with a mild climate, while Sydney is a bit cold in winter.
If you spend money, the tuition fees of the two universities should be similar. The cost of living in Brisbane is lower.
If you work part-time and pay taxes, it should be about the same, and so should black workers. How much money you can earn from a part-time job depends on what kind of work you do and your personal ability.