Probably very localised, but in Melbourne (Australia) we found the minimum cost for a nanny was $18/h with some wanting up to $35/h, but that was rare. We found our nanny through a web site (findababysitter.com.au) where we could search by availability, locality, and such.
Most wanted to take cash in hand, others wanted us to pay them like an employee (tax, superannuation). Some wanted money for car expenses.
We tried going through an agency once but found they added little value.
We asked for recommendations in our daughter school newsletter - this led to one lead.
We asked friends who had or had had nannies - this led to one hire that lasted 6 months.
BTW, what we found was:
- the market is full of uni students looking for an easy gig. We went through perhaps 100 resumes, 20 interviews and hired perhaps 5 nannies. They come and go.
- there were few professional nannies. Look for people wanting to be in the childcare area, teachers or nurses.
- an 18 year old with 0 effective experience would be asking for the same rate as someone with 10 years experience
- most were crap and had little interest in children, they just wanted
play money while getting there degree. That being said, some were fantastic.
I also worked at home while the nanny took care of our son. Eventually, my son reach 3 and we put him in childcare - he got the social exposure he needed, we got reliable childcare and saved a bit of money.