Actually giving it for free to those who already own the old AoK wouldn't be a great option. It might not look like a big remaster, but with nothing else but the old sprites to work with it's not that easy to improve on them without spending some good time on it. Also, the old games could still be found in certain stores for $5,- those $5 would go to the store, not the studio that actually worked on this re-release. Not to mention, the work that would need to be done to see if anyone has a real old AoK with the cd-keys all over the web. It would cost them more then they could make on the Steam sales. And games simply are being sold above their price at release, that's just how today's market works. Probably this summer it will go for $10 at the steam summer sale. If it's to expensive for you, just wait it out.