I don't have enough money to watch all the movies I like, and will buy DVDs only in Blu-Ray if I really like the movie. That new Kubrick DVD collection that came out in May is kind of what I'm referring to, although I don't think I'll buy it [anytime soon] because $100 and some odd dollars is a bit more than I can justify spending on DVDs when I can spend it on more practical, essential things at the moment.
So I'll do what Ebert does. See if Netflix has it on instant, then check Hulu, then if it's old enough, I'll check if it's streamed on public domain sites, then I'll see if I can rent on Amazon. If I can't find it by then I'll pirate it.