It's not that they are getting greedy, it is that they have no choice but to raise prices if they want to keep the titles available at all. If you read the article that I linked, you'll find that it is because the movie studios have MASSIVELY raised the licensing fees that Netflix has to pay them, and in some cases the studio is capping the number of times that a catalogue can be accessed via streaming. Last year Netflix paid $180 million for their streaming rights; the prediction is that 2012 is going to cost them $1.98 billion.
It was great while it lasted, but now that the initial contracts that they set up when the company was founded are beginning to expire, the major studios want a piece of the profit, and they are in a position to see that they get it. If they don't, Netflix will die very quickly, because if they don't pay up, all they will be offering is old TV shows and independent films.