We can't buy calendars here in Australia through Apple, but I just discovered that if you control-click in a blank area of the calendar preview pane, you can save the calendar as a PDF to print on your own printer.
This is actually in the iPhoto help, but its not obvious in the interface; only the big 'Buy Calendar' button seems obvious.
[robg adds: I'd never noticed this contextual menu before either; the menu also lets your use Preview to view the calendar, or Clean Up the calendar.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060803005453200