[quote name='opportunity777']Pass. I'm not a fan of STEAM, but I guess this is a good deal for people who use the service.[/quote]
Note that a lot of the DOS-ish Steam games don't actually require Steam to run, just to download. With all of the DOS X-Com games, you should be able to buy the game, download it, then do whatever you want with the directory. (Specifically, X-Com 1, 2, and Apoc (as well as Commander Keen) all work after copying them to a Linux machine. Interceptor gives a Steam error though.)
This is, of course, assuming your problem is with the Steam DRM. (Which I really don't like either.)
Of more general interest, it appears the Steam version of X-Com is the DOS version, as opposed to the Windows port included with the PC Gamer CD, which is nice in a "more likely to actually work" kind of way.