The current Humble Bundle features a bunch of Star Wars games that you can redeem in Steam. First tier of games is JKA, KotOR, and Dark Forces! That means you can get all three of those for $1.
If you're not familiar with the Humble Bundle, its a donation sort of thing where you donate a certain amount to get a certain number of games. Usually a really good deal.
Even if you already have the disc versions of these games, its always good to have a digital copy as a backup! With steam, its just in your account so you can download it at any time, as many times as you need, essentially.
https://www.humblebundle.com
