As a frugal single guy I too am quite impressed by the numbers shown here.
Transport : $18 p/w
Car Fuel : $70 p/w
Coffee/Snacks etc : $25 p/w
Rego/Insurance : $75 p/w
Meals outside of home : $100 p/w
I am still living at home and spend $288 p/w ! Those who are on <$100 p/w probably do not have a car and are superbly frugal!
When I was single and at uni - I was living in Ashwood for about a year with a relative , didn't have a car but hitched rides to most parties or push biked it (mainly around the Burwood area - stayed overnight if I was too drunk).
I estimate I was probably spending $75-$100 a week back then.