Steam will flat out ban you if they find out you're buying out of region. I used to buy games for brits all the time, now I'm squeamish.
The reason being, to combat piracy in certain regions, steam was selling games for steam sale level prices. They found out people in the $50 region were buying games for $2, and punished them for doing so. This reminds me of how in San Diego we pay out the ass for gasoline, simply because they can.