Don't be naive. Sure, if you have a small sum of gold buried in the yard, it can hold its value through times of political uncertainty. But to exercise any meaningful opposition to a despotic government, you need to be rich ( in order to pay people to do your will) or well-organized (in order to urge them via the media). In the former case, you can be taxed - governments levying taxes on the very wealthy usually goes down well with the much poorer majority - and in the latter, you can be declared a subversive and censored.
You might find it instructive to examine the history of ancient Rome around the time of Nero and Caligula. If you find history books dry reading, get a copy of 'I, Claudius' which presents the history of that period in narrative form and is both educational and entertaining.
This is not to say that opposition to a tyrannical government is hopeless - indeed, history with littered with examples of such leading to revolution. But currency alone is a weak check on a determined oppressor. And (as we are sadly reminded by news from Africa on a regular basis) revolutions often result only in a change of players, but the game remains the same.
