I’d say part of the problem lies with the responsibility to fix the potholes.
If I’m not wrong, the fixing of potholes falls under the councils (at least those potholes not in Motorways and such). And I’ll bet that each council has different budgets and priorities.
Sprinkle a bit of border arguments if a pothole happens to be between councils, and you’ve made yourself a nice plate of Not My ProblemTM!
I also wonder how much the population and area of Sydney affect this. Higher volume of cars degrades the road faster. Maybe we should use a measure of “potholes per capita” to be able to do an accurate comparison.
Have you tried a Surf store? DFO might have some outlets worth checking.
Otherwise, thrifty shopping. Take a day trip to the Northern Beaches and check their local Vinnie’s/Salvos, I’m sure they’ll have something nice for a low price.