Sydney cost of living is too expensive and been going up every year and I've lived here almost all my life and only been recently been tempted to move somewhere more affordable.
So even the ones who live here are getting priced out of our own city.

But if your here its better to get food from the supermarkets and never convinience store or gas station. You easily pay 2-4 times the price. Those chocolate bars are often $1 at woolworths and can get a 1.25l of coke for under $2.

Catch public transport instead of driving for most places even beaches unless there's 4-5 of you to split fuel/parking/hire costs.

Night life especially getting drinks or going to clubs have gotten far more expensive after Sydney lockout laws. My last fancy cocktail cost me $50 and the exact same one when I travel to Philippines would be around $3.

Fast food like McDonalds have special lunch time deals but outside of those the price has sky rocketted. I used to be able to buy a Medium burger meal for around $8 last time I had one last year. This year it was almost $14 trying to grab the same for dinner. Ended getting food elsewhere.