Wikipedia has numerous pages depicting currencies, but check the copyright status of images – many of have restrictions. The image on the right, for example, is copyrighted by the European Central Bank, but its usage is allowed.
It is easy to turn chocolate coins into attractive clipart for Pages. For how-to read this previous article.
And an overview of where to find clipart already installed on your Mac (that's why there is no special 'clipart' folder in iWork) read: Clipart for iWork/Pages - Where Is It?
|20 euros from 'Travel Journal' template|
|2 euro coin|
This is the copyright note to the Wikipedia image of eurocoins: The image above depicts a unit of currency issued by the European Central Bank (ECB). This design is copyrighted by the ECB, and its use is permitted by ECB, "as long as reproductions in advertising or illustrations cannot be mistaken for genuine banknotes" and [for coins] "for photographs, drawings, paintings, films, images, and generally reproductions in flat format (without relief) provided they are in faithful likeness and are used in ways which do not damage or detract from the image of the euro".