I picked this up recently from Gamestop, it's a great simulation game. Reminds me of the Settlers and the old Caesar games. It's a real-time game, but with more emphasis on building your colonies rather than fighting.
It also works with no problems in Windows Vista, so no worries there.
Also, to the TC, the version on sale is the gold edition which comes with the expansion pack, The Sunken Dragon. It's a great value, considering most places have the original by itself for $20. I recommend editing the title.