When I was at USTDC, the exchange rate for US dollars to New Taiwan (NT) dollars was forty to one. I think today's rate is about thirty to one. The local currency at that time was as shown above.
If you were buying anything on base, you used US dollars. If you bought anything off-base, you were supposed to use only NT, though some merchants would offer you a better deal on some items if you agreed to pay in US dollars...or so I heard anyway.
I remember cashing my paycheck and asking for a stack of NT notes to pay my rent at the hostel every month, with a little bit extra for routine expenses like the houseboy, taxis and local shopping. It was just one of those rituals that most everyone did on payday.
American military people stationed around the world today still go through the same process every month, except that there's direct-deposit and now they have ATMs that spit out both US and local currencies.