You can freely use many foreign driver's licenses without extra expenditures.
An international driving permit which uses a standardized format and includes translations may be required.
Not true in many EU countries. In France you're supposed to get a French driving license after two years of residence. Never heard of this being enforced, but I know people that changed when their licensed needed renewal so they could deal with a local administration.
That's in contrast to people from some non EEA countries who have to take a local driving test.