Can u buy CDs?

Ok, well, I am lokking for CDs for games who's CDs I have lost. IS there anywhere that I can buy just the CDs? I already have all of the CD keys. This should be prefectly legal as I own the Key and what not. If you think the site is questionable, please dont post it, but feel free to PM.
Mods- If this is ou tof line please by all means delete it.
Thnx.

usually you can get in touch with the manufacturer, and they'll send you a replacement for a couple bucks. Lots of times, this info is in the manual, buried in the mouseprint. You usually have to provide proof you bought it, tho. I did this on a lost X-COM floppy, waaaay back in the day

Pretty much any other way is illegal, as far as the company is concerned.