Polaroid i-Type film is currently on sale for $17 at David Jones, saving $10 from the usual retail price of $27. It is rare to have specials on Polaroid film, so this seems to be a good deal.
You can also sign up for David Jones mailing list which gives out $10 ‘birthday’ vouchers, potentially bringing the film down to $7.
Keep in mind this is i-Type film which is designed to work with Polaroid i-Type cameras, not with vintage Polaroid cameras. That said, the only difference between i-Type film and regular Polaroid 600 film is that these film packs don’t contain the batteries, which are required for vintage cameras to work. If you have an old film pack at home with batteries in it then you can fairly easily take the film out of these packs and put them in a pack that contains batteries. Obviously this needs to be done in the dark or you will ruin your film.