Hi
I recently discovered that pages in iwork 09 can export to epub
it wasn't the worst experience ever it wasn't perfect by any stretch but it did get me a file i could edit in Sigil.
However Apple have a template epub_best_practices.zip and I downloaded it and it wouldn't open complaints of missing index.xml
it turns out that Apple being Apple had updated it to a later version of pages.
This was a bit of a disaster not only wouldn't the template open the newer version of pages was pretty much panned by everyone who had the good 4.03 version of pages.
However I managed to find the missing template in a dusty part of the internet
now i can't promise that pages will be very good with your epub but you should be able to edit the css into something reasonable with the text having appropriate classes even if the style isn't what you want.
It seems a reasonable way to generate epub and pdf files from the pages word processor.
Anyway i've attached the original template, have fun