This just cements my opinion that, unless you're dying to play something right away, there's simply to reason buy downloadable games retail, ever. I paid more for Psychonauts, for Earthworm Jim, for Fallout, for Giants, and so on, and so on.
But you know what? The prices I paid were still really, really good, and GOG.com is a fantastic site, so I'm not complaining--just observing. Digital distribution, for all its flaws, can actually make us say things like "I can't believe I paid $4.49 for Earthworm Jim 1 & 2! I'm such a sucker!" Strange times.
Now, to finally get Sacrifice (and probably many, many other games).
Edit: Also, thanks, OP!