Games should cost whatever you find them worth after playing, IMO.
I'm a bit of a communist myself.
even after completing them? I use to pirate some games myself because they lack a proper demo, but I always got the game if I liked it at the point I wanted to play it more than few minutes. Sadly even if in the past PC gamers used to have demos for every game out there now console gaming almost killed this way of doing, and when there's a demo sometimes you even get the demo only after a preorder!
I'm not condemning you about piracy but it's not nice to say "your game should be free, you're not doing it for love" to a developer that spent all his work time and prolly most of his free time too on a game for a year or more.
Also as you can afford valve and $50 DS games you could affort $10 for Zero Gear, those aren't only money "for games", are money for people you should admire as they're trying to follow their passion even if they're forced
to sell their games to live.
I had to quit my job too to try this way, luckily I've always worked in the industry but a lot of people did shitty jobs just to pay the rent dreaming about a day when they could afford doing games full-time instead of delivering pizzas or cleaning floors.
Now marshmonkey and his team are just trying that so the last thing you should say to them is that they're being greedy asking for some bucks
I'd love to set the game I'm working on for free without the need to use money to live, but it's not going to happen to anyone unless their parents\wife\whatever are so rich and so dumb letting them doing games at their expenses
@Hempuli: World of Goo giveaway was an HUGE success, but it was a sale, after months and months the game was already out both for wii and pc. I'm sure Zero Gear will be on sale too at some time or will have a price drop after about a year or so