That's truly my main beef with Steam. Often retail games can be had considerably cheaper via shopping around, but on Steam, they're full price unless they decide to have a deal. Not only that, but with digital distribution, no one is paying for DVD pressing, the box, manual (which is usually a non-issue since most games don't have good manuals anymore), store space, shipping, blah blah blah.
Yet we pay retail on Steam and can get it for less AT retail?
Lame. I'm hoping that's altered as digital distribution becomes the norm.
If I weren't addicted to having games at my fingertips on Steam, and if they didn't have such great sales when it suits them, I'd stick to retail.