Welcome to hell.

Neither are valid justifications for piracy and to use them as if they are valid arguments is idiotic. If something is too expensive, don't buy it! I didn't buy Machinarium, as I thought it was more than I wanted to pay, but I also didn't pirate it. The second argument is weak because everyone I know in real life who pirates games buys them if they think, for some reason, the game is unpirateable (or the DRM isn't cracked for a few days). Anecdotal evidence? Yes, but it shows that pirated games = lost sales. Not 1 to 1, but a significant amount of lost revenue.

You do of course realize what you say flies in the face of pretty much all economic theory. Would no pirates buy the game if it couldn't be pirated? Of course not, that is extreme. But a price of 0 dollars vastly changes demand, more people will acquire it at this price than 20 dollars. To suggest that a similar number of folks will acquire the game at a 20 dollar price point (i.e. if piracy is somehow impossible) is simply not true. Stating piracy amounts to "a significant amount of lost revenue" is rather specious. You need data that you simply do not have to back that up. If you want to know the myriad ways conventional wisdom lies to you, please pick up a copy of Freakonomics and give it a read.
Also, I might suggest some of your pals are toolbags base upon your description of their behavior:)

Yeah, if there's no demand for it at $20, they will lower the price. However, at any price you'll get piracy. People pirate $3; they pirate $1 games; they pirate free games (yes, it happens).
Any amount of revenue lost is significant. Are you going to argue money isn't significant for indie devs?

Significant: important or of consequence.
Yes, I will argue that any amount of money is not significant for the vast majority of people. You waste money on convenience, frequently, at least statistically. Almost everyone does this. You pull up to the McDonald's drive through, every time you pay someone to do something you could have managed yourself, every time you drop a piece of change and don't bother chasing it across the floor, every time you don't sell your scrap metal or recycle a bottle with a deposit on it, every time you've failed to properly get a rebate form mailed off, and lastly every time you don't clip a coupon for something you buy (or forget your coupon and buy it anyway). You might not do all these things, but the average person does.
Some amounts of money are insignificant and it certainly varies by individual and amount. To imply some unverified amount of lost sales representing some unknown amount of lost money is de facto "significant" is specious. You are making assumptions about a number of variables that you cannot possibly know anything about for certain.

For any indie dev, $20 is a significant amount of money. Indie devs often measure their sales in the thousands (or even hundreds). I know, for certain, that if Machinarium could not be pirated, it would have sold at least 3 additional copies, for a total of about $60 (assuming they purchased it from the company's website) or about $40 (if it was sold on a DD service).
Now, if you want to hide behind hand-waving to argue that $40 isn't important to indie developers, go ahead. I know some people who make indie games for a living, and they appreciate every dime they get. Each sale is significant to them.
Wasting money on convenience does not equate to losing money due to a pirated copy.

I'm not arguing that the amount they lost to piracy is or isn't significant. What I most certainly am arguing is that you have insufficient information to argue that it is, especially in all cases.
I Made A Game With Zombies (without the leet spelling, sorry) sold over 160,000 units. Retail price was 80 XBox Live points ($1 USD), according to http://www.gamerbytes.com/2010/01/indepth_xbox_live_indie_games.php that guy made 112,000 dollars. IIRC he made the game in around 3-6 months. That is a lot of units.
I have no idea how many units of Machinarium sold, since afaik the devs have not said. So, what if they sold 100,000 units at 20 bucks apiece? Are they still suffering so much from pirates? Are you as outraged? What if they only sold 100 units? Does your outrage change?
We aren't even talking about pirated copies that could, in theory, be converted to sales yet.
Anytime someone releases a piece of information like they have I am immediately suspicious. By itself it doesn't mean much, but it sure does incite a lot of feelings on both sides. I encourage you to not jump to conclusions. This data is nearly meaningless save as a publicity stunt.
They do have a self interest in the publicity, which is sales. I don't begrudge them that, it's fine, but don't read too much into incomplete information. As well, I'm not accusing them of falsifying data, but it's not like falsification of data is uncommon in cases where there is a financial self interest.
I'd be fascinated to see their books and look at the raw data. It's the only way to get an actual case study in the effects of piracy.

I agree. It's always a good thing to voice your feedback.
But, they're a business, not a charity. Why not take advantage of the sale? I think you have too much money, Ali Baba:)

Says the guy from UAE ;p
one of the few countries in the world who build masssssssssssssssiiiiiiiiiivvvvvvvvveeeeeeeeeeeee
mmmmmmmmaaaaaaaaaaaassssssssssiiiiiiiiiiiveeeeeeee
Islands....
Damn... i spent a night in Atlantis my last time through there... holy cow....

Same here, though Telltale's Monkey Island games was a lot better than their previous stuff.
I might get this... I got Machinarium when I was still a Steam fan and have since downloaded a DRM-free copy elsewhere. I don't feel like a pirate for that, I paid $20 for the game, but I guess $5 more their way for an "official" DRM-free copy isn't so bad, and I get the soundtrack.

Good call, the soundtrack is great.

Such articles always make me shake my head. The moment they neatly split pirates and customers without any overlap is the moment they're talking with their heads up their asses. Many of these "stupid pirates" try before buying for starters.
An even bigger amount of pirates pirate for the sake of trying a game despite having little interest in it. There's been several surveys which showed that something like 80+% of all pirates do so because they're curious and wouldn't ever have paid for the game. This is why a pirated game is not a lost sale but I think it's vital to recognize the strength piracy has towards giving a game publicity. You'd be surprised how many reviews on game sites and posts about the game on forums come from pirates who, along this way, give the game more exposure.
In the end, yes, piracy has a negative impact. But it has some benefits too - it lets people discover a game they're willing to buy. And if they don't buy this one, they may buy the sequel. It's not all negative and bad. And if people try it and don't like it, I think they deserve the right to return the game but these days that's no longer possible so no surprise piracy is used the way it is today.

Uh...there's a Machinarium demo right there on their browser; no need to install anything (except for Flash player, probably), so using that excuse is not really justifiable in this case.

If its only for trying there are demos for most of the games. I think the negative impacts always outweigh the positive ones from piracy. The only way to go is to not buy a game or asking friends if they let you play with their systems. I think this is okay.