http://www. softwarefirst.com has Prophecy Gold with a couple of other games for an excellent price, and the games (even though from UK) work fine. Gold includes extra disk with Secret Ops missions. Ended up being a pretty decent retailer actually... (Hope this doesn't break any rules, just passing on reccomendation for anyone looking for it, took a while to find).
They only have the "3-games-in-one edition" though..., i.e. Wing Commander Prophecy Gold & Alpha Centuri & Red Alert.
Good to get Secret Ops, but for those looking for collectibles, not getting the original box might be a disappointment... (okay, I'm really nitpicking here... )
The item's price is £17.99... i.e. around $30.00, a very fair price for 3 games!