So ... sleepy ... must ... keep working...
I am now the proud owner of a kosher copy of Wing Commander: The Kilrathi Saga -- go, me! It showed up on eBay this morning with a "Buy It Now" price of $95, and I pounced. It is theoretically possible that I might have gotten it for less, but not likely -- it often goes for $150 - $300, depending on the condition.
The one I got is just the disks, no manuals or packaging. But now I can play the Secret Mission expansion, have music, and a clear conscience. ;)
I'm gonna call it my berfday present to myself. ;)