Using a mortgage broker generally means no direct costs to you but there will be a couple of unavoidable costs there. These may include:
A Registered Valuation ($800 - $1,200)
Solicitor Costs ($800 - $1,500)
LIM report ($150 - $400)
Builder's Report ($100 - $500)
Weather Tightness Report for Monoclad houses ($300 - $1,000)
Finance fee for non-bank lending (~1%)
Prices can vary. Always request a quote before ordering a report.  For a list of property professionals that you'll likely work with, see our article here.