Which areas of eastern suburbs sydney are (relatively) affordable to buy property for families?
Relatively is certainly the appropriate word Adam -- the 5 or 6 I would suggest are most affordable in order, especially for families are:
Phillip Bay/Little Bay
Matraville (David Warner's origins)!!
All of the median prices of these range from circa $1.3 to $1.55 m
The answer depends on what your price expectations are and what size and type of property you are seeking. In general terms, the Easter suburbs are not affordable for most. You'll need to go quite a way out into the suburbs to find any properties in the 'affordable' price category. Happy to have a chat offline if you would like and see if I can help.