Danke Sophil!

Bin jetzt um einiges schlauer. Hab mir auch die Online-Ausgaben von englischen Zeitungen angesehen - die verwenden meistens ein Plural-s (also dollars, euros, pounds).

Aber eine eindeutige Antwort gibt es anscheinend nicht - scheint also sehr länderspezifisch zu sein.

I can speak at least for the US and GB. (Beyond the US and GB, itt may be laenderspezifisch, but I doubt it.) For one dollar it's dollars; for more than one, it's dollars.

- He owes me a dollar.
- He owes me $1.75 [spoken: "a dollar seventy-fix", or "one seventy-five"]
- He owes them $15,000 [spoken: fifteen thousand dollars].

But in a compound you'd say "dollar".
- The US Treasury has announced plans to issue a redesigned $20 bill [pronounced: twenty dollar dollar bill].
- If I give you a $1 bill [spoken: a one dollar bill], will you give me four quarters [quarter = 25 cents]?

The same with cents. I believe in Euro-land you say cent in the singular. In the US, dollars and cents are both usually spoken in the plural when referring to more than one.