Where have you been? I spotted this kind of thing years ago and it's not just itunes that do it, I've found with anime in particular they have a habit of doing that. You pay a huge amount just for a couple of episodes when it first comes out only to have a complete set come out a few months later for much cheaper. Here's a tip, whenever you want to buy something wait a few months until after they've released for the price to drop or what you can buy to become more reasonable.
I'm 99% certain they do this specifically to take advantage of the desperate people who just want to get the thing right away, if you want to watch it right away but don't want to pay the outrageous release date prices, download it from bittorrent so you know what you're in for and if it's good enough pay for it later this works for me the majority of the time and saves a lot of money with everything, not just t.v shows. This is just a theory but I reckon the fact that you can essentially preview everything with Bittorrent right now in full is why the major entertainment industries hate filesharing so much since it takes away their advantage over people.
