As far as I'm aware there's no such thing as a good price anymore but I believe the Impossible Project is the main resource, there or evil-bay.
Andy
Not sure mate. If you hang on a minute our resident Polaroid expert (Ped) will be along with all the news thats fit to print.
Andy
Reporting for duty!!
I've never had a 300, but yes you're right, Polaroid and Fuji make the packs. Amazon is probably a good bet. You can also get limited edition films with pictures of Disney characters or people like Spongebob Squarepants on the borders I think.
Show us some pictures when you're done!
Cheers