Star Control 2, one of my favorite games of all time, seems to be missing from a lot of download services (GOG, I'm looking at you). Does anyone know where one could download/purchase a copy of this game for the PC without paying $100 on amazon or e-bay? 
 
A follow up question: What would one have to do to get it running properly on a modern machine?

Have you tried this: http://sc2.sourceforge.net/ ?

At some point the developer released the source code so people have been working on remaking the game for free download. Im not sure how far along it is, though it could also be complete, but you can download and play it now.