Am I reading this correctly?

The above is from the Steam store. 30GB? For an RTS? This isn't Max Payne is it?

PCGamer has it at 20GB, while other sites state 12. That's a bit ridiculous.

The beta is currently taking up just under 8 gigs, so I find that final figure highly suspicious.

Seems like a number pasted there when Steam just isn't sure how large a game will really be.

Phew - I hope that's the case.

The requirement means a hard drive with at least 30GB of free space on it. The game will not take up a full 30GB, but you should always leave some empty space on a HDD as headroom, and it's common for game system requirements to factor this in. The idea is that if the requirement said exactly how much space the game takes up (say, 10GB), some people would read that requirement and then install the game on a hard drive with only barely enough space (10.4GB free), and then they may encounter problems when running the game or doing other things with that hard drive, in spite of technically meeting the system requirements.