If safety is your most important concern, then I'd recommend Dandenong Ranges Area eg: The Basin, Ferntree Gully, Olinda or Monbulk, all suburbs are a 40 min drive to melbourne CBD
here are some cheap listings in the area, (as the area is mid range) - all options are 3 bedroom housing.
Kilsyth-https://www.realestate.com.au/property-townhouse-vic-kilsyth-133506894 this property costs $650k New Townhouse.
Upper Ferntree Gully- https://www.realestate.com.au/property-house-vic-upper+ferntree+gully-135524178 This property is $525k-575k it's a renovated home.
If you have any other queries let me know, (the suburbs that I just listed are one of the safest suburbs in the whole of victoria, the only disadvantage is driving, because it is the mountainside.)