Thanks for confirming!
I think it must be something going on with STEAM as well. I haven't been able to solve the issue, but i installed STEAM on another computer and the full download size shows correctly.
Too bad there's no way this laptop can handle the game! grrr
So, a steam/computer issue, not a game one.
I'll be able to play this game eventually >.< maybe i'll try reinstalling steam completely. I think I can do that without having to reinstall all my games from scratch.