@Redstar In some locales (South America for instance) you do have to pay by month (though you can buy a permanent subscription for the same cost as the US box.) http://www.joystiq.com/2010/05/07/starcraft-2-offering-subscription-plans-in-latin-america-asia-a/

I run the game on a 6-year old AMD64 3500+ with a 7600GT PCI Express 256MB video card and 2GB of system RAM. Way way way below recommended specs, and even below required specs. It runs fine and looks fine even though I have to turn down settings. One of the things Blizzard is very very good at (among many) is making scalable games.