i want to buy a house, can i?

This maybe a stupid question, people may attack me. But still I would love some feedback from the others.

I earning $70000/ Annual. My partner is staying home to look after my baby daughter.

I am living in innerwest area Sydney. Surround here all the 2brm apartment is around 400k+ , the weekly repayment will be $700+ if I borrow 320k for 30 yrs.

How can I afford $700 per week for a 2 Brm apartment if only I am working?

I really want to know when I can buy a home.

Is that my fault, I do not have a rich parent