So your family member is across the city, I'm assuming there will be a minimum amount of time that you would take to visit them even if there was no traffic. Presumably, when you originally made whatever living arrangements you are in now, you factored that minimum time and was probably okay with that. That is, you essentially curbed your own freedom of movement based on some physical limits and other priorities.
Presumably, that limit is a function of the way the roads were designed, and a straight road directly from your apartment to your loved ones would have been faster. Though you probably didn't complain then how the city wasn't designed to enable your freedom of movement.
How is this new congestion pricing any different? Did it discriminate against you personally in any way? In fact, it probably reduced your commute time, by making you pay more. Im guessing that Sydney probably has some assistance for people who actually can't afford this price, which you probably didn't qualify for (guessing since you're here at HN), so I'm really struggling to sympathize with your argument of how it curbs your freedom of movement (unless you're poor and there's no assistance from the government for you).
We all have many freedoms but almost none of them are free. In fact they all come at great costs. 30 dollars doesn't actually sound that high all things considered.