Well, I bought it anyway for $2.99. I'd say the Mac soundtrack, wallpaper, and the backup copy are worth it. Although, I still have my original CD's from about 15+ years ago so I've not been concerned about a backup copy! My main regret is getting rid of the awesome box for the dos cdrom version of Descent 1. I wish I could find an HD scan of that!
For anyone who's really interested in HD descent wallpaper, you have a few options. The D1X/D2x Rebirth and D2X-XL sites have some pretty good wallpapers but I prefer gog.com's mainly because it's not as busy and has some space for icons. They Pyro looks a little like it's been stretched to make it HD but otherwise, it's a nice addition. There is only one gog.com wallpaper with this game.
http://www.descent2.de/wallpaper-downloads.html http://www.dxx-rebirth.com/wallpapers/
The main reason using google's image search for hd wallpaper actually won't help much is because this is an old game mainly played during an era of lower-def 4:3 screens. Also, you'll have fun trying to filter out the movie in your search.