1. If you go on Battle.net and put in your old Starcraft CD key (doesn't matter which version...I did it with the Power Mac system 8 version CD), they will upgrade you to a free digital download Starcraft Anthology compatible with 2000, XP, Vista and/or Mac OS X...no patching required. that includes an up-to-date battle.net CD key. For XP its a 1.2GB download so make sure you have a good connection. I had to turn off peer-to-peer to increase the speed.
So yes, if you have the original StarCraft, you get treated like you own both (it and Brood War)...because the Anthology is essentially the download version of the Battlechest. I would do this soon, because you never know with Activision. They certainly don't have to support an old game this way.
2. If you don't have any of the original StarCraft disks or key codes, then Amazon currently has the StarCraft Battlechest for $9.99. The next nearest price I could find is $12.90 new at Gogamer.com. The average price (Gamestop for one) is $19.99. The full price for the Anthology direct from battle.net is $14.99.
3. eBay may have it for cheaper (I've seen both Brood War and the original campaign for $2 + $3 shipping), but I'm not sure what happens if its used and the code is already registered...so caveat emptor.
Please note that I have tried this on XP SP3 and Mac OS X 10.5 (Leopard). See within the thread for more detailed info on troubleshooting Vista, Windows 7 (32 & 64 bit).
Edited by bigwightdog, 28 July 2010 - 07:09 PM.