Can always move north of Sydney and commute like the majority do! Rents around Hornsby & Central Coast ( eg Gosford) are alot cheaper!
I was paying $220 AUD per week for a 4 bedroom townhouse, lug, pool, tennis court etc at Narara.... 5 mins from freeway.. hornsby is a little dearer than the coast bout $280 - $350 AUD pw for something along the same lines....
Gosford to the city by train is about an hour and ten mins by train... hornsby around 40 mins from memory....