If you look next to each Avatar season compilation title, it says how many discs come with your rental. For the S3 compilation it says '4-Disc Series.'
That's all four discs to S3. There aren't any more than that.
Netflix only rents Avatar by the season compilation apparently and not by the individual DVDs.
It's not a mistake because I know of at least one person who has actually rented this compilation and has already seen the finale thus far.
I cannot believe Nickelodeon would end Avatar like this? I mean three years and we are now reduced to finding out the uber-awesome, epic ending to Aang's story through children's books and now available to rent a month and a half before it is set to air on Nick?
I don't get it?