A 20 hour+ single player campaign, and a multiplayer experience so good that it's played at stakes of tens of thousands of dollars is "1/3 of a game"?
Any time a sequel is released on the same engine, it's just "part of the other game"? Every expansion pack is a complete money-grabbing rip-off? Or do you only say this because with SC2, it's pre-planned?
Even if it is $180 or whatever, I think 60 hours of one of the best RTS campaigns ever, as well as the best multiplayer RTS (and even if you disagree with the quality of the game, the community still trounces any other ones) is well worth it.
To me, most of the game is the online multiplayer. Most of that will move out of the reach of people who don't buy Heart of the Swarm the moment Heart of the Swarm releases. I think it's appropriate to say that a player who only buys Wings of Liberty received 1/3 of the game, since he will no longer be able to play online multiplayer with a large pool of worthwhile opponents.
I also think the game is worth the $120-$180, and I definitely plan on buying the remaining two pieces.
Even if it is $180 or whatever, I think 60 hours of one of the best RTS campaigns ever, as well as the best multiplayer RTS (and even if you disagree with the quality of the game, the community still trounces any other ones) is well worth it.