When can we move out?

My boyfriend and i will finish our degrees at the end of 2016 (civil/mining engineering and law respectively). We both live with our parents and so our cost of living is only about $5200 pa between us for food and entertainment. Between us we can expect to have saved only about $12,000 from part time jobs during uni. If we want to live and work in sydney (earning about $110,000 pa between us) how long before we can afford to buy a modest apartment? What would the interest be like on a loan that size?